"How do I resolve the Reformation? Is it faith alone that justifies, or is it faith and works? Very simple. No tricks. On this issue I believe Luther was simply right; and this issue is absolutely crucial. As a Catholic I feel guilt for the tragedy of Christian disunity because the church in the fifteenth and sixteenth centuries was failing to preach the gospel. Whatever theological mistakes Luther made, whatever indispensable truths about the Church he denied, here is an indispensable truth he affirmed — indispensable to union between all sinners and God and union between God’s separated Catholic and Protestant children."
It is interesting to find a Roman Catholic author saying anything nice about either the Reformation or Martin Luther... but the quote just seems too good to be true. Based on the context below, I would caution Protestants from utilizing this quote from Peter Kreeft because... it is too good to be true. There are indeed "tricks" going on.
Documentation
The version above was cut-and-pasted from an Internet discussion forum. It was posted without any documentation. Kreeft's comment appears in a published book: Peter Kreeft, Fundamentals of the Faith: Essays in Christian Apologetics (San Fransico: Ignatius Press, 1998). Via Google books, the quote can be found here and here.
The fourth issue is the most crucial of all. It is the issue that sparked the Reformation, and it is the issue that must spark reunion too. It is, of course, the issue of faith, of faith and works, of justification by faith.
This is the root issue because the essence of the gospel is at stake here. How do I get right with God? This was the issue of the first century church at Galatia, a church Protestants see as making the same essential mistake as the Catholics-preaching the gospel of good works. Protestants dare not compromise on this issue or they would be turning to what Paul calls "another gospel". Thus his harsh words to the Galatians, the only church for which he has not one word of praise:
"I am astonished that you are so quickly deserting him who called you in the grace of Christ and turning to a different gospel-not that there is another gospel, but there are some who trouble you and want to pervert the gospel of Christ. But even if we, or an angel from heaven, should preach to you a gospel contrary to that which we preached to you, let him be accursed."
How do I resolve the Reformation? Is it faith alone that justifies, or is it faith and good works? Very simple. No tricks. On this issue I believe Luther was simply right; and this issue is absolutely crucial. As a Catholic I feel guilt for the tragedy of Christian disunity because the church in the fifteenth and sixteenth centuries was failing to preach the gospel. Whatever theological mistakes Luther made, whatever indispensable truths about the Church he denied, here is an indispensable truth he affirmed-indispensable to union between all sinners and God and to union between God's separated Catholic and Protestant children.
Much of the Catholic Church has not yet caught up with Luther; and, for that matter, much of Protestantism has regressed from him. The churches are often found preaching one of two "other gospels": the gospel of old-fashioned legalism or the gospel of new-fangled humanism. The first means making points with God and earning your way into heaven, the second means being nice to everybody so that God will be nice to you. The churches, Protestant and Catholic, may also preach the true Christian gospel, but not often enough and not clearly enough and often watered down and mixed with one of these two other gospels. And the trouble with "other gospels" is simply that they are not true: they don't work, they don't unite man with God, they don't justify.
No failing could be more serious; but on the Catholic side, as distinct from the liberal Protestant side, it is a failing in practice, not doctrine. When this happens, the Catholic Church fails to preach its own gospel. It is sitting on a dynamite keg and watering the fuse; it is keeping a million dollar bank account and drawing out only pennies. Catholicism as well as Protestantism affirms the utterly free, gratuitous gift of forgiving grace in Christ, free for the taking, which taking is faith. Good works can be only the fruit of faith, flowing freely as a response to the new life within, not laboriously, to buy into heaven.
But there are two important verbal misunderstandings in the Reformation controversy over faith and works. First, when the Council of Trent affirmed, contrary to Luther, that good works contribute to salvation, it meant by salvation not just getting to heaven but the whole process of being transformed and becoming incorporated into the life of God. In other words, salvation meant not just justification but sanctification as well; and it was quite correct to say that both faith and works contribute to sanctification, thus to salvation.
Second, Catholic and Protestant theologians mean different things by the word faith. Protestants usually follow biblical usage: faith means saving faith, the heart or will accepting Christ. Catholics usually follow a more technical philosophical and theological usage: faith means the act of the mind, prompted by the will, which accepts Christ's teachings as true. In Protestant language, faith means heart faith, or whole-person faith; in Catholic language, faith means mind faith. Thus, Catholic theologians are right to deny justification by faith alone in that sense (which of course was not Luther's sense). For "the devils also believe, and tremble." in this narrower sense faith can exist without the works of love; as James writes, "Faith without works is dead." In the larger sense, faith cannot exist without works, for it includes works as a plant includes its own blossoms.
Existing side by side in pre-Reformation theology were several ways of interpreting the righteousness of God and the act of justification. They ranged from strongly moralistic views that seemed to equate justification with moral renewal to ultra-forensic views, which saw justification as a 'nude imputation' that seemed possible apart from Christ, by an arbitrary decree of God. Between these extremes were many combinations; and though certain views predominated in late nominalism, it is not possible even there to speak of a single doctrine of justification. [Jaraslov Pelikan, Obedient Rebels: Catholic Substance and Protestant Principle in Luther’s Reformation [New York: Harper and Row, 1964, 51-52].
All the more tragic, therefore, was the Roman reaction on the front which was most important to the reformers, the message and teaching of the church. This had to be reformed according to the word of God; unless it was, no moral improvement would be able to alter the basic problem. Rome’s reactions were the doctrinal decrees of the Council of Trent and the Roman Catechism based upon those decrees. In these decrees, the Council of Trent selected and elevated to official status the notion of justification by faith plus works, which was only one of the doctrines of justification in the medieval theologians and ancient fathers. When the reformers attacked this notion in the name of the doctrine of justification by faith alone—a doctrine also attested to by some medieval theologians and ancient fathers—Rome reacted by canonizing one trend in preference to all the others. What had previously been permitted (justification by faith and works), now became required. What had previously been permitted also (justification by faith alone), now became forbidden. In condemning the Protestant Reformation, the Council of Trent condemned part of its own catholic tradition [Jaroslav Pelikan, The Riddle of Roman Catholicism (New York: Abingdon Press, 1959), pp. 51-52].
First, when the Council of Trent affirmed, contrary to Luther, that good works contribute to salvation, it meant by salvation not just getting to heaven but the whole process of being transformed and becoming incorporated into the life of God. In other words, salvation meant not just justification but sanctification as well; and it was quite correct to say that both faith and works contribute to sanctification, thus to salvation.
Here's an interesting YouTube link in which Scott Hahn wrote Peter Kreeft about this very issue. In the letter, Kreeft says (at around 1:40) that he "confused the truth in Luther, sola gratia, with the untruth, sola fide."