Luther: "It cannot be proved by the scriptures, that infant baptism was instituted by Christ, or begun by the first Christians after the apostles"

The Lutherans on the CARM board have been going at it with a few Baptists over infant baptism. Here's what caught my attention:

Martin Luther, the great father of the Reformation, says: "It cannot be proved by the scriptures, that infant baptism was instituted by Christ, or begun by the first Christians after the apostles. Apud Van. Inf. Bapt., part 2, p. 8.
Why are you Lutherans opposing your founder ?? [source]

The person citing this quote said he cited his source (Apud Van. Inf. Bapt., part 2, p. 8). This refers to a secondary source: "Vanity of Infant Baptism" by "R.A." or "A.R." from 1642, London. He then used this source for documentation (which cites the same thing). The quote certainly has been used frequently by Baptists. As I looked around for it, I didn't find any primary source citations. In regard to Vanity of Infant Baptism, one old author states:

This work was published in 1642. I have not been able to obtain it, but from the attention which was paid to it on both sides, we may naturally infer that it was then considered a work of a good deal of consequence. Dr. Featley has belabored this "tractate of A. R., entitled The ranitie of childrens baptitme," in fifteen pages of his Dippers' Dipt, that was published in 1645. He bestows upon the work and its author a large portion of those opprobrious epithets for which he was peculiarly distinguished. It is mentioned with much respect by Crosby, Ivimey, and other baptist historians; and in Teasdale's historical discourse, relative to the history of the first baptist church in New Haven, Conn., he informs us that Mrs. Eaton, the wife of the first Governor of that province, became tinctured with baptist sentiments from reading this book, which was loaned to her by lady Moody. This took place in 1664. The full name of the author I have never been able to learn.

[Edited to add: Tony Byrne of Theological Meditations submitted the following:

It appears that you are referencing "The second part of the vanity and childishnes of infants baptisme wherein the grounds from severall Scriptures usually brought for to justifie the same, are urged and answered. As also the nature of the divers covenants made with Abraham and his seed, briefly opened and applied." by Andrew Ritor [A.R.]. It seems that this work is available on EEBO (Early English Books Online) according to WorldCat. The first part of Ritor's work (which has nothing about Luther in it) can be obtained online here (click), but I don't think the second part is available online.]

And also:

"Concerning the time when Infants Baptisme was first invented, Luther in his Booke of Anabaptisme acknowledgeth, that it cannot be proved, by Sacred Scripture, that childrens Baptisme was instituted by Christ, or begun by the first Christians after the Apostles, for one thousand yeares since it came to be in use in the church, and was established by Pope Innocentius." A. R. [Andrew Ritor], The Second Part of the Vanity and Childishness of Infants Baptisme (London, 1642), 8.

Tony Byrne's help established that the quote in question isn't actually a direct quote. It's a summary statement based on Luther's treatise, Concerning Rebaptism (1528). I suggest if you really want to know what Luther felt about this subject, read the entire treatise. This is only a snippet of an extended argument (Luther makes multiple points).

In the second place, this is an important consideration: No heresy endures to the end, but always, as St. Peter says, soon comes to light and is revealed as disgraceful. So St. Paul mentions Jannes and Jambres and their like [II Tim. 3:8f.], whose folly is finally plain to all. Were child baptism now wrong God would certainly not have permitted it to continue so long, nor let it become so universally and thoroughly established in all Christendom, but it would sometime have gone down in disgrace. The fact that the Anabaptists now dishonor it does not mean anything final or injurious to it. Just as God has established that Christians in all the world have accepted the Bible as Bible, the Lord’s Prayer as Lord’s Prayer, and faith of a child as faith, so also he has established child baptism and kept it from being rejected while all kinds of heresies have disappeared which are much more recent and later than child baptism. This miracle of God is an indication that child baptism must be right. He has not so upheld the papacy, which also is an innovation and has never been accepted by all Christians of the world as has child baptism, the Bible, faith, or the Lord’s Prayer, etc.

You say, this does not prove that child baptism is certain. For there is no passage in Scripture for it. My answer: that is true. From Scripture we cannot clearly conclude that you could establish child baptism as a practice among the first Christians after the apostles. But you can well conclude that in our day no one may reject or neglect the practice of child baptism which has so long a tradition, since God actually not only has permitted it, but from the beginning so ordered, that it has not yet disappeared.

For where we see the work of God we should yield and believe in the same way as when we hear his Word, unless the plain Scripture tells us otherwise. I indeed am ready to let the papacy be considered as a work of God. But since Scripture is against it, I consider it as a work of God but not as a work of grace. It is a work of wrath from which to flee, as other plagues also are works of God, but works of wrath and displeasure. (LW 40:255-256)

Addendum
A Lutheran on the CARM boards maintains that the Luther's Concerning Rebaptism is not the source of the obscure quote in question.

I lean towards the translation of the obscure quote to be either a different translation or a less accurate translation. I believe it is an "actual quote" that may have morphed over the years originating from Luther's Concerning Rebaptism.

I've been through a number of situations like this. The secondary work referred to: "Apud Van. Inf. Bapt" dates from 1642. This tells me that if someone in 1642 had access to Luther's writings, they probably only had access to Luther's most popular writings. Brecht notes that Concerning Rebaptism is Luther's only major work against Anabaptist theology (there is a sermon from Luther on this topic that was often available as well throughout the centuries). As I've discovered in just about every instance of secondary Luther citations from the 16th-17th centuries, the primary source was not some unknown letter or lesser-known writing. Interestingly (at least to me) is that one of Luther's earliest papal critics (Cochlaeus) cites the same sort of sentiment against Luther (using Concerning Rebaptism), that Luther held that infant baptism cannot be proved from Scripture. In other words, this charge against Luther came on the scene early and gained popularity early, and did so because of Luther's writing, Concerning Rebaptism.

Often, if one finds a Luther citation that dates back to a secondary source from either the 16th or 17th Centuries, there can a wide dynamic range in the translation. Without having access to "Apud Van. Inf. Bapt," it's hard to know exactly which source the author used. Did he rely on another secondary source (like Cochlaeus), did he have a German copy of the treatise, or did he have a translation of the German in another language? When the quote was revised by from the old English to new English, did it morph is some way? This probably accounts for the slight variations between the LW translation and that allegedly taken from Apud Van. Inf. Bapt.

Probably the most humorous example of the misuse of a Luther quote I've been involved with was when I nailed Roman apologist Steve Ray for mis-citing Luther. Ray brought in two of his buddies, one a self-professed Pro-Romanist apologist, the other a lawyer, all spending weeks and weeks trying to prove I had the wrong source, and that the quote Steve Ray was using is from an unknown source that's out there somewhere. The quote Ray was using similarly dated back to secondary sources from the 16th and 17th Centuries. Some of Ray's buddies reluctantly agreed I had it right all along, Ray though still holds out the possibility that some mysterious Luther writing putting his particular spin on the quote he used may be out there.

Luther on the Death of Unbaptized Infants

This is a follow-up to my previous post, Calvin on the Death of Non-Elect Infants and the Age of Accountability.

Here's an interesting quote from Luther as to what happens to child who is not baptized. In his treatise, Concerning Rebaptism (1528), Luther presents a number of reasons why "Anabaptism" is wrong:

First, because child baptism derives from the apostles and has been practiced since the days of the apostles. We cannot oppose it, but must let it continue, since no one has yet been able to prove that in baptism children do not believe or that such baptism is wrong. For even if I were not sure that they believed, yet for my conscience’s sake I would have to let them be baptized. I would much rather allow them baptism than to keep them from it. For if, as we believe, baptism is right and useful and brings the children to salvation, and I then did away with it, then I would be responsible for all the children who were lost because they were unbaptized—a cruel and terrible thing. If baptism is not right, that is, without value or help to the children, then I would be guilty of no greater sin than the Word of God had been spoken and his sign given in vain. I would not be responsible for the loss of any soul, but only of an ineffectual use of the Word and sign of God.    (LW 40:254)

Luther's position in not quite the Roman Catholic position. For Romanism, a child receives grace in baptism without faith. Luther states in a Postil sermon:

This they have inferred from the former opinion, that little children receive grace in this way without faith, solely by the virtue and power of the sacrament, as, they dream. Therefore they also ascribe the same thing to adults and to all men, and utter such things from their own mind, and thereby they have in a masterly way eradicated and made void and unnecessary the Christian faith, and have set up human works alone by virtue of the power of the sacraments.

Of course, Rome has an entire theological development on what happens to an unbaptized infant. There was "Limbo" up until fairly recently. Self-proclaimed interpreter of Romanism Jimmy Akin commenting on Rome's recent Limbo development states,

The document that the International Theological Commission has been working on concerning limbo has now been published. AS ANTICIPATED, it casts doubt on the doctrine of limbo without claiming anything certain regarding the fate of infants dying without baptism, instead encouraging an attitude of hope regarding their salvation.This is in line with the development of Catholic thought in the last few decades regarding the fate of such children, as well as the discussion of their fate in the Catechism.

Addendum: The Most Effective Baptism is Infant Baptism
For Luther, the most effective baptism was infant baptism:

I maintain as I have written in the Postil that the most certain form of baptism is child baptism. For an adult might deceive and come to Christ as a Judas and have himself baptized. But a child cannot deceive. He comes to Christ in baptism, as John came to him, and as the children were brought to him, that his word and work might be effective in them, move them, and make them holy, because his Word and work cannot be without fruit. Yet it has this effect alone in the child. Were it to fail here it would fail everywhere and be in vain, which is impossible. (LW 40:244)

And in his Postil sermon:

Therefore we here conclude and declare that in baptism the children themselves believe and have their own faith, which God effects in them through the sponsors, when in the faith of the Christian church they intercede for them and bring them to baptism. And this is what we call the power of alien faith: not that anybody can be saved by it, but that through it as an intercession and aid he can obtain from God himself his own faith, by which he is saved.

32. So here we also say, that children are not baptized in the faith of the sponsors or of the church; but the faith of sponsors and of the church prays and gains faith for them, in which they are baptized and believe for themselves. For this we have strong and firm Scripture proof, Mt 19,13-15; Mk 10, 13-16; Lk 18, 15-16. When some brought little children to the Lord Jesus that he should touch them, and the disciples forbade them, he rebuked the disciples, and embraced the children, and laid his hands upon them and blessed them, and said: "To such belongeth the kingdom of God" etc. These passages nobody will take from us, nor refute with good proof. For here is written: Christ will permit no one to forbid that little children should be brought to him; nay, be bids them to be brought to him, and blesses them and gives to them the kingdom of heaven. Let us give due heed to this Scripture...

So we also say here, that children are brought to baptism by the faith and work of others; but when they get there and the pastor or baptizer deals with them in Christ's stead, he blesses them and grants to them the faith and the kingdom of heaven: for the word and deed of the pastor are the word and work of Christ himself.

I think it's interesting that Luther limits the power and efficacy of baptism. He staunchly maintains the absolute power of baptism in infant baptism, but yet limits the power of baptism in adults:

I think, if any baptism is certain, the baptism of children is most certain, because of the Word of Christ, where he commands to bring them, whereas the adults come of themselves. In adults there may be deception because of the reason that is manifest; but in children there can be no deception, because of their hidden reason, in whom Christ works his blessing, even as he has bidden them to be brought to himself. It is a glorious word and not to be treated lightly, that he commands us to bring the children to him, and rebukes those who forbid it.

Typically my blog entries on Luther are interested in simply presenting the historical evidence. Whether or not I agree with Luther's position is irrelevant. I personally don't follow Luther's reasoning here (and yes, my position is still irrelevant!). Since when is the regenerating power of God thwarted by a human will? I think if Luther were consistent here, an unbelieving adult being baptized (whose family and church were praying for him as in, "the faith of sponsors and of the church prays and gains faith for them," that person, according to Luther, should similarly receive the gift of faith.

Here's an interesting link as well: Sola Fide Compromised? Martin Luther and the Doctrine of Baptism. One may disagree with the conclusions of the author, but he does a good job laying out Luther's position on baptism.

A Primer on Luther's View of Baptism For Non-Lutherans

I've recently come across a number of Lutheran-related discussions on baptism. More often than not, the majority of non-Lutherans in these exchanges have little understanding of the Lutheran position, and to make matters worse, very few Lutherans in these discussions appear to actually have the ability to explain their view succinctly and cogently to those who oppose it. This makes for a heated discussion with little or no substance or progress from either side.

I don't claim to have any sort of expert knowledge on the various strands of Lutheranism, but it should be possible to read the historical record of what Martin Luther said on baptism and outline his view.  To understand an historical position does not imply that one must agree with that position. However, if one wants to respond effectively, one must first demonstrate an understanding of that which one opposes. I offer the following to my non-Lutheran friends in an effort to help clarify at least Luther's view. Whether or not the particular Lutheran you're interacting with holds this view or not is up to you to determine. As you read each of the points below, ask yourself  if you to agree or disagree with Luther's view. I've also added some related questions to consider. In other words, as the explanation moves along, try and pinpoint where you actually have the disagreement with Luther's view.

For my Lutheran friends, I would indeed welcome any comments or clarifications on Luther's view of baptism. If I've taken Luther out of context or missed something substantial in his theology, I would appreciate any corrections or clarifications.

BC= Book of Concord
LW= Luther's Works (English)

1. Baptism is a Form of God's Word
One of the first keys to unlocking Luther's view is that for Luther, baptism is a form of God's Word. Therefore, to reject the crucial importance of baptism or think of it as a  human "work" is to reject God's Word and God's work. Just like when one reads the pages of Scripture and hears the very voice of God promising that if one trusts in Christ alone and Christ's work that person will be saved, so to in baptism, God promises that baptism "effects forgiveness of sins, delivers from death and the devil, and grants eternal salvation to all who believe, as the word and promise of God declare" (BC, 348).

Question: Do you think that baptism is a form of God's Word? Is this sacrament another way in which God communicates?  Is minimizing the significance and importance of baptism akin to taking God's Word for granted?


2. The Sacrament of Baptism is a Divine Promise Attached to an Outward Sign
In one of Luther's early writings (1520), The Babylonian Captivity of the Church, Luther argued the sacraments collectively were divine promises (God's Word) attached to outward signs (Baptism, the Lord's Supper, etc.). The promise is that God will forgive sins. It isn't the water of baptism that forgives sins, it's the Word of God connected with the water (BC 349).

Question: Can God's Word be "attached" to a sign? Is there Biblical precedent establishing this basic principle? Is it similar to the Old Testament temple and such things like the Ark of the Covenant and the slabs in which God wrote the Ten Commandments?


3. Our Personal Faith Must Trust God and His Promises Conveyed in Baptism
The basic structure of Luther's theology of baptism is a triad of divine promise, sign, along with a third thing: faith. An atheist can read God's promise to forgive his sins, but does this mean such a person merely reading the words has salvation? In the same way, if one were to force a group of atheists into a Lutheran church to be baptized, does this mean that such a group has been saved by such a baptism? Of course not.

In Luther's historical context, Rome taught that the sacraments gave God's grace to everyone who does not block that grace with mortal sins. Luther responded,

These adversaries of mine and all their masters up to the present time cannot show how the priest remits guilt unless they do so by advancing that heretical but usual opinion which says that the sacraments of the new law give justifying grace to those who place no obstacle in the way. But it is impossible to proffer the sacrament in a salutary manner except to those who already believe and are just and worthy. The one who approaches the sacrament must believe [Heb. 11:6]. Therefore it is not the sacrament, but faith in the sacrament, that justifies. (LW 31:106)

Luther says elsewhere on the essential role of faith:

"Therefore let us open our eyes and learn to pay heed more to the word than to the sign, more to faith than to the work or use of the sign. We know that wherever there is a divine promise, there faith is required, and that these two are so necessary to each other that neither can be effective apart from the other. For it is not possible to believe unless there is a promise, and the promise is not established unless it is believed. But where these two meet, they give a real and most certain efficacy to the sacraments. Hence, to seek the efficacy of the sacrament apart from the promise and apart from the faith is to labor in vain and to find condemnation. Thus Christ says: “He who believes and is baptized will be saved; but he who does not believe will be condemned” [Mark 16:16]. He shows us in this word that faith is such a necessary part of the sacrament that it can save even without the sacrament, and for this reason he did not add: “He who does not believe, and is not baptized.” [LW 36:67].

Question: According to this quote from Luther, can the administration of Baptism on a person without faith ultimately save that person? According to this quote from Luther, can a person be saved without being baptized?


4. Infant Faith and Baptism 
The question then arises that if baptism only has effect when faith grasps the promise of grace in the sign, why should infants be baptized? Why baptize an infant that can't demonstrate a fides viva (living faith)? Luther's position on baptism developed on this issue but did not contradict itself.

Early on Luther simply relied on the medieval notion that a child was baptized into the faith of others (the faith of the church and the faith of the parents). Luther stated:

Therefore we here conclude and declare that in baptism the children themselves believe and have their own faith, which God effects in them through the sponsors, when in the faith of the Christian church they intercede for them and bring them to baptism. And this is what we call the power of alien faith: not that anybody can be saved by it, but that through it as an intercession and aid he can obtain from God himself his own faith, by which he is saved. It may be compared to my natural life and death. If I am to live, I myself must be born, and nobody can be born for me to enable me to live; but mother and midwife can by their life aid me in birth and enable me to live. In the same way I myself must suffer death, if I am to die; but one can help to bring about my death, if be frightens me, or falls upon me, or chokes,crushes or suffocates me. In like manner, nobody can go to hell for me; but he can seduce me by false doctrine and life, so that I go thither by my own error, into which his error has led me. So nobody can go to heaven for me; but he can assist me, can preach, teach, govern, pray and obtain faith from God, through which I can go to heaven. This centurion was not healed of the palsy of his servant; but yet he brought it about that his servant was restored to health. 32. So here we also say, that children are not baptized in the faith of the sponsors or of the church; but the faith of sponsors and of the church prays and gains faith for them, in which they are baptized and believe for themselves. For this we have strong and firm Scripture proof, Mt 19,13-15; Mk 10, 13-16; Lk 18, 15-16. When some brought little children to the Lord Jesus that he should touch them, and the disciples forbade them, he rebuked the disciples, and embraced the children, and laid his hands upon them and blessed them, and said: "To such belongeth the kingdom of God" etc. These passages nobody will take from us, nor refute with good proof. For here is written: Christ will permit no one to forbid that little children should be brought to him; nay, be bids them to be brought to him, and blesses them and gives to them the kingdom of heaven. Let us give due heed to this Scripture.

  As the Reformation progressed, the radical Anabaptists forced him to define his position with more depth. In the mid 1520's, Luther wrote about children actually demonstrating they did indeed have faith. A favorite example I've come across in his writings is John the Baptist moving in his mother's womb when near the womb of the Virgin Mary. Doesn't such a Biblical example prove that a child can most certainly have some sort of faith? For Luther therefore, a child should be baptized and that child may receive the promises attached to the sign of the sacrament of baptism. Luther says,

That the Baptism of infants is pleasing to Christ is sufficiently proved from his own work. God has sanctified many who have been thus baptized and has given them the Holy Spirit. Even today there are not a few whose doctrine and life attest that they have the Holy Spirit. (BC 442)

for Luther, the best time to baptize someone is during infancy:

I maintain as I have written in the Postil that the most certain form of baptism is child baptism. For an adult might deceive and come to Christ as a Judas and have himself baptized. But a child cannot deceive. He comes to Christ in baptism, as John came to him, and as the children were brought to him, that his word and work might be effective in them, move them, and make them holy, because his Word and work cannot be without fruit. Yet it has this effect alone in the child. Were it to fail here it would fail everywhere and be in vain, which is impossible. (LW 40:244)

But that infant faith doesn't simply remain intact and steadfast. It's the responsibility of a child's parents and church to nurture a child's faith:

We bring the child with the purpose and hope that he may believe, and we pray God to grant him faith. But we do not baptize him on that account, but solely on the command of God. Why? Because we know that God does not lie. My neighbor and I — in short, all men — may err and deceive, but God’s Word cannot err. (BC 444)

One of the main differences between Lutherans and the Reformed concerns the gift of faith. For a Reformed person, faith, while it may have times of great confidence and great weakness, can never be lost. For a Lutheran, faith can also have times of great confidence and great weakness but can be lost. The Reformed typically don't speak about the gift of faith being given to an infant during baptism while Lutherans do. That gift of faith given to a child in infancy, if not nurtured, can be eternally lost.  Both of these views on faith and infant baptism must be distinguished from the Roman Catholic view during Luther's day. Luther describes the view as follows:

21. Now the question is, what becomes of the young children, seeing that they have not yet reason and are not able to believe for themselves, because it is written in Rom 10, 17: "Belief cometh of hearing, and hearing by the word of Christ." Little children neither hear nor understand the Word of God, and therefore they can have no faith of their own. 22. The sophists in the universities, and the sects of the pope have invented the following answer to the question: Little children are baptized without their own faith, and on the faith of the Church, which the sponsors confess at the baptism; thereupon the infant receives in baptism the forgiveness of sins by the power and virtue of the baptism, and faith of its own is infused with grace, so that it becomes a new born child through the water and the Holy Spirit. 23. But if you ask them for the proof of this answer and where this is found in the Scriptures, it is found up the dark chimney, or they will point to their doctor's hat and say: We are the highly learned doctors and we say so; therefore it is true, and you must not inquire any farther. For almost all their doctrine has no other foundation than their own dreams and imaginations... 24. From this falsehood they have gone farther and have even come to the point, where they have taught and still teach, that the sacraments have such power, that even if you have no faith and receive the sacrament (provided you have no intention to sin), you shall still receive the grace and the forgiveness of sins without faith. This they have inferred from the former opinion, that little children receive grace in this way without faith, solely by the virtue and power of the sacrament, as, they dream. Therefore they also ascribe the same thing to adults and to all men, and utter such things from their own mind, and thereby they have in a masterly way eradicated and made void and unnecessary the Christian faith, and have set up human works alone by virtue of the power of the sacraments.

Question: Is is possible for an infant to have faith? According to the Luther quotes from the Book of Concord, is Luther affirming that every child that is baptized has the same sort of faith that the pre-born John the Baptist had? what are the differences between the Romanist view and Luther's view of infant baptism? Are the differences substantial or insignificant?


5. Baptism Should Not Be Based on the Faith of the Person Being Baptized
By the late 1520's and early 1530's, Luther strongly argued against basing baptism on the faith of the person to be baptized (See specifically his treatise, Concerning Rebaptism (LW 40). The Anabaptists were blatantly denying infant baptism. According to Luther their basic error was grounding baptism in human faith. Here's Luther's reasoning:

a) Baptism is God's activity. Our faith can fluctuate, but God's promise in the sign of baptism always remains. Throughout Luther's writings one can find him exhorting his readers to look back to the seal of baptism and God's promises contained therein. This recollection is a helpful remedy to someone in times of doubt and despair.

b) Even if someone's baptism was incorrectly administered, such would not negate God's promises.

c) Our lack of faith cannot negate our baptism in the same way Israelites acting incorrectly voided God's covenant with them.

d) Most importantly, faith itself is not something that can be ostensively measured like picking up a rock. That is, the Anabaptists did not have the ability to look into another person's heart and know with certainty someone actually had faith. The Anabaptists therefore really couldn't baptize anyone if baptism can only be administered on someone with faith. The Anabaptists could theoretically baptize someone 100 times and not really know with certainty if the person truly had faith.

For Luther therefore, the divine word of promise in baptism was intimately connected with human faith (but was not grounded on faith). There was the sign / promise and the faith that grasped the sign. Depending on what Luther was writing, he either emphasized one or other without contradicting either. In writing against Romanists he opposed the notion that baptism was salvific without faith. Writing against the Anabaptists, he emphasized the work of God in baptism- that baptism really does contain God's promises, and even if administered to an unbeliever, it is still a form of the Word of God.

Question: If baptism is a form of God's Word, does Luther make any valid points about basing baptism on faith? In other words, does his reasoning here follow based on the premises outlined above (1-4)? Is Luther's reasoning in #d a strong epistemological argument or not? That is, if baptism is only given to those who profess faith, what guarantee is there that the person being baptized truly has faith?


6. Treating Baptism Indifferently is Sinful
When one approaches Luther's Large Catechism, one finds the themes mentioned above. As his exposition begins, Luther treats Baptism with the respect and importance it deserves.

a) Baptism is God's commandment. If we claim to be Christians and "regard it as an indifferent matter, then, like putting on a new red coat" such a person will not be saved (Mark 16:16). Luther specifically has the Anabaptists in mind here. Baptism isn't simply common water, but God's Word added to it. To treat baptism flippantly therefore is to deny God's Word. Can a true Christian deny God's Word? No! That's why someone who treats baptism indifferently will not be saved. such a person demonstrates no faith in God's promises. for someone to emphasize faith and minimize baptism is nothing else than placing faith in opposition to the Word of God in the sacrament.

b) A little bit later Luther addresses faith in regard to baptism:

Our know-it-alls, the new spirits, assert that faith alone saves and that works and external things contribute nothing to this end. We answer: It is true, nothing that is in us does it but faith, as we shall hear later on. 29 but these leaders of the blind are unwilling to see that faith must have something to believe — something to which it may cling and upon which it may stand. Thus faith clings to the water and believes it to be Baptism in which there is sheer salvation and life, not through the water, as we have sufficiently stated, but through its incorporation with God’s Word and ordinance and the joining of his name to it. When I believe this, what else is it but believing in God as the one who has implanted his Word in this external ordinance and offered it to us so that we may grasp the treasure it contains?

30 Now, these people are so foolish as to separate faith from the object to which faith is attached and bound on the ground that the object is something external. Yes, it must be external so that it can be perceived and grasped by the senses and thus brought into the heart, just as the entire Gospel is an external, oral proclamation. In short, whatever God effects in us he does through such external ordinances. No matter where he speaks — indeed, no matter for what purpose or by what means he speaks — there faith must look and to it faith must hold. 31 We have here the words, “He who believes and is baptized will be saved.” To what do they refer but to Baptism, that is, the water comprehended in God’s ordinance? Hence it follows that whoever rejects Baptism rejects God’s Word, faith, and Christ, who directs us and binds us to Baptism.

Note the last sentence: those who reject baptism (or as he stated earlier: treat it with indifference) are denying God's Word. Such a person will not be saved. Then Luther states:

32 In the third place, having learned the great benefit and power of Baptism, let us observe further who receives these gifts and benefits of Baptism. 33 This again is most beautifully and clearly expressed in these same words, “He who believes and is baptized will be saved,” that is, faith alone makes the person worthy to receive the salutary, divine water profitably. Since these blessings are offered and promised in the words which accompany the water, they cannot be received unless we believe them whole-heartedly. 34 Without faith Baptism is of no use, although in itself it is an infinite, divine treasure. So this single expression, “He who believes,” is so potent that it excludes and rejects all works that we may do with the intention of meriting salvation through them. For it is certain that whatever is not faith contributes nothing toward salvation, and receives nothing.

Question: When Luther states, "Hence it follows that whoever rejects Baptism rejects God’s Word, faith, and Christ, who directs us and binds us to Baptism," to what sort of person or group is he referring? What does Luther mean when he uses the words, “He who believes and is baptized will be saved"?

7. Baptism is not a Human Work
Luther's Large Catechism also explains why baptism is not a work:

35 However, it is often objected, “If Baptism is itself a work, and you say that works are of no use for salvation, what becomes of faith?” To this you may answer: Yes, it is true that our works are of no use for salvation. Baptism, however, is not our work but God’s (for, as was said, you must distinguish Christ’s Baptism quite clearly from a bath-keeper’s baptism). God’s works, however, are salutary and necessary for salvation, and they do not exclude but rather demand faith, for without faith they could not be grasped. 36 Just by allowing the water to be poured over you, you do not receive Baptism in such a manner that it does you any good. But it becomes beneficial to you if you accept it as God’s command and ordinance, so that, baptized in the name of God, you may receive in the water the promised salvation. This the hand cannot do, nor the body, but the heart must believe it.

37 Thus you see plainly that Baptism is not a work which we do but is a treasure which God gives us and faith grasps, just as the Lord Christ upon the cross is not a work but a treasure comprehended and offered to us in the Word and received by faith. Therefore they are unfair when they cry out against us as though we preach against faith. Actually, we insist on faith alone as so necessary that without it nothing can be received or enjoyed.

Question:  Why would Luther argue that baptism is not a human work? Which person or group during Luther's lifetime would say baptism is a human work, and why?

Conclusion
This is simply a short review of Luther's view as I understand it. Don't be surprised to find much lengthier treatments of Luther's view on baptism. A good selection of material can be found in What Luther Says by Ewald Plass  (18 pages consisting of two columns on each page!). See also The Theology of Martin Luther by Paul Althaus  pp. 345-374. Also, I've cited this Postil sermon from Luther a few times above. It's a good overview of Luther's position on infant baptism

Addendum #1
As an addendum, I've attached some material I posted a few weeks ago in response to Chris Pinto.  In that post I chastised Mr. Pinto for not really describing Luther's view of baptism, but picking and choosing what agreed with his own view. Mr. Pinto clung to the notion that Luther held faith could save without baptism, citing this quote from What Luther Says:

145 Faith Saves without Baptism Not Baptism Without Faith
A person can believe although he is not baptized; for Baptism is no more than an external sign to remind us of the divine promise. If one is able to get Baptism, it is well. Then one should take it, for no one should despise it. But if one were not able to get it or one were denied it, he is nonetheless not damned provided that he believes the Gospel. For where the Gospel is there Baptism also is and everything a Christian needs, because damnation follows upon no sin except unbelief alone. This is also the reason why the Lord says: "He that believeth not shall be damned." He does not say: He that is not baptized; but is silent about Baptism. For Baptism is useless without faith. It is like a letter to which seals are attached but in which nothing has been written. Therefore he who has the signs (which we call Sacraments) and not faith has seals only, seals attached to a letter without any writing. (W 10 III, 142 - E 12, 196 - SL 11, 953 f)

Pinto concludes that Luther's views on baptism are much like his own and what modern evangelicals believe. He says he agrees with Luther that "water baptism is not necessary for salvation." Obviously as demonstrated above, Luther's view of baptism isn't as simple as Pinto claims it is. In fairness to Mr. Pinto though, there are other comments from Luther about faith saving rather than sacraments:

It cannot be true, therefore, that there is contained in the sacraments a power efficacious for justification, or that they are “effective signs” of grace. All such things are said to the detriment of faith, and out of ignorance of the divine promise. Unless you should call them “effective” in the sense that they certainly and effectively impart grace where faith is unmistakably present. But it is not in this sense that efficacy is now ascribed to them; as witness the fact that they are said to benefit all men, even the wicked and unbelieving, provided they do not set an obstacle in the way—as if such unbelief were not in itself the most obstinate and hostile of all obstacles to grace. To such an extent have they exerted themselves to turn the sacrament into a command and faith into a work. For if the sacrament confers grace on me because I receive it, then indeed I receive grace by virtue of my work, and not by faith; and I gain not the promise in the sacrament but only the sign instituted and commanded by God. Thus you see clearly how completely the sacraments have been misunderstood by the theologians of the Sentences. In their discussions of the sacraments they have taken no account either of faith or of promise. They cling only to the sign and the use of the sign, and draw us away from faith to the work, away from the word to the sign. Thus, as I have said, they have not only taken the sacraments captive, but have completely destroyed them, as far as they were able. (LW 36:67)

Furthermore, St. Paul says in Rom. 14[:23], “Whatever does not proceed from faith is sin.” How, then, can the sacraments give grace to unbelievers who in all their works and ways do nothing else than sin so long as they do not believe. Indeed, how can they remove the obstacle if they remain in that unbelief which makes all that they do sin, as St. Paul here states? Yet they teach that faith is not necessary in order to receive the sacraments and grace and, condemning me, they condemn these clear passages of Scripture. For the same reason, St. Paul quotes in Rom. 1[:17] and Heb. 10[:38] the saying of the prophet Habakkuk as one of the chief articles in all Christian teaching when he says, “The righteous shall live by his faith” [Hab. 2:4Open in Logos Bible Software (if available)]. He does not say that the righteous shall live by the sacraments, but by his faith, for not the sacraments, but faith in the sacraments, gives life and righteousness. Many receive the sacraments and obtain from them neither life nor godliness, but he that believes is godly and will live. That is also the meaning of Christ’s saying in the last chapter of Mark [16:16], “He who believes and is baptized will be saved.” He puts faith before baptism for where there is no faith, baptism does no good. As he himself afterwards says, “He who does not believe will be condemned,” even though he is baptized, for it is not baptism, but faith in baptism, that saves. For this reason, we read in Acts 8[:36f.] that St. Philip would not baptize the eunuch until he had asked him whether he believed. And we can see every day that wherever in the whole world baptism is administered, the question is put to the child, or the sponsors in his stead, whether he believes, and on the basis of this faith and confession, the sacrament of baptism is administered. (LW 32:13-14)

Moreover, St. Paul says (Rom. 10[:10]) that, “A man believes with his heart and so is justified.” He does not say that it is necessary that he receive the sacraments, for one can become righteous by faith without the bodily reception of the sacraments (so long as one does not despise them). But without faith, no sacrament is of any use, indeed, it is altogether deadly and pernicious. For this reason, he writes in Rom. 4[:3] that, “Abraham believed, or trusted, God, and it was reckoned to him as righteousness” or godliness. This Moses had previously written in Gen. 15[:6] and it was set down in order that we might know that nothing makes us good and righteous except faith. Without faith, no one can have any dealings with God, nor receive his grace. (LW 32:15)

For the word can exist without the sacrament, but the sacrament cannot exist without the word. And in the case of necessity, a man can be saved without the sacrament, but not without the word; this is true of those who desire baptism but die before they can receive it. (WA 38:231)

Addendum #2
Here's an interesting overview from A.A. Hodge on the Lutheran view of the Necessity of Baptism:

41. What is the Lutheran view ?

Their standards state the necessity of the sacraments without apparent qualification (See “Aug. Confession” Art. 9, and “Apol. Aug. Confession,” p. 156, quoted under last chapter). But Dr. Krauth has shown from the writings of Luther and their standard theologians, that their actual view was that (1) baptism is not essential (as e. g., Christ’s atonement is), but that (2) it is necessary, as the ordained ordinary means of conferring grace, yet (3) not unconditionally, because the “necessity” is limited (a) by the possibility of having it, so that not the deprivation of baptism, but the contempt of it condemns a man, and (b) by the fact that all the blessings of baptism are conditioned on faith. (4) Baptism is not always followed by regeneration, and regeneration is not always preceded by baptism, and men may be saved though unbaptized. (5) That within the church all infants are saved although unbaptized. (6) As to infants of heathen, the point undecided, because unrevealed, but hopeful views entertained.––Krauth “Conserv. Reform.,” pp. 557–564. Hodge, A. (1996). Outlines of Theology. Index created by Christian Classics Foundation. (electronic ed. based on the 1972 Banner of Truth Trust reproduction of the 1879 ed.) (628). Simpsonville SC: Christian Classics Foundation.