About two years ago I loaned the book On Being a Theologian of the Cross: Reflections on Luther's Heidelberg Disputation, 1518 to a good friend. I haven't seen it since. I was pleased to see that Google books now has it available, and it appears to be back in print. This is one of my favorite Luther-related books. It isn't as dull as it sounds. In fact, I'd rather someone read this small book than an in-depth treatment of Reformation history. This book taught me one of the main arteries of Luther's theology: the distinction between glory and the cross, and those "theologians" that espouse one or the other.
The theology of the cross is a theology of foolishness. It denies man’s wisdom and works; it rests totally upon Christ’s work. Indeed, it really does sound silly to think that salvation is found only through faith alone. Shouldn't we have to do something? Hasn't God given us an innate ability to reach out to Him? Or, hasn't God poured out some sort of enabling grace through a sacrament that frees us to make a choice to serve him? The theologian of the cross says no. God doesn't need our help at all. He saves by grace alone through faith alone. God explained it in of all things, a book. Imagine that: God almighty explained Himself for us, not in a majestic show of power and grandeur, but in frail book. In that book, He explained how God himself, the most supreme power and creator of all things became a helpless baby in a crib. He grew up to be hung on a cross, naked, weak, and suffering. God almighty was killed as a common criminal. He then rose from the dead. The book then details that savingly believing in His perfect active and passive work, peace is made between the Holy God of the universe and the sin-burdened human being. This is the foolishness of the theology of the cross.
All the worlds’ religions reason that God can only be appeased by some work on our part. But a theologian of the cross finds it is only in God’s action where we find salvation. On the other hand, the theology of glory is founded on man’s wisdom and works. It is a worldview that seems “sensible and right” by worldly standards. Glory theologians have to "understand" by the use of reason, and they have to “do” by their own moral energy to be right with God. God's a fair guy, they "reason." A fair God would enable us to at least be able to do "something" to save ourselves. Wouldn't a smart God would want an infallible official to lead His people? I mean, simply leaving a book and an fallible person in charge of the church seems.... utterly foolish. People wouldn't be able to know anything certain with just a book and some fallible people running a local church. That's just stupid. A smart God would set something up like a small kingdom, governed by an infallible head. He'd probably send glorious signs and wonders to prove it's His set up. That would be the smart thing to do. In fact, one of those miracles could be something like the body of woman in a glass case that doesn't decay after 100 years, or perhaps a holy woman could appear here and there and give new signs. That would be wise, wouldn't it? Everyone needs more proof than just... what's stated in a book.
The late medieval church that Luther was confronted with was a church filled with “glory.” By “glory,” Luther meant that the emphasis was not on the achievements of Christ, but on the achievement of the Roman Church, and those achievements were accomplished by the churches’ own power. Luther encountered the theology of glory in three different ways (ht: Robert Kolb):
First he encountered the glory of “human reason” expressed in his earlier scholastic training. Scholastic theology had been strongly influenced by Aristotelian metaphysics, and this influence had misshaped the Biblical method. Think of the confusion caused by the Quadriga's fourfold interpretation of Scripture and it's ability to obscure the Gospel.
Secondly, Luther was confronted with the glory of human effort (works). He encountered this in his monastic order. Think of the counsels of the perfect. Imagine people believing that they could perform works to attain a standard of holiness that would allow them to stand before a Holy God, or that some such sacrifice in this life makes one "a saint" in the next.
Thirdly, he also rejected the “glory of the church” and said the church is a suffering church, rather than a church of beauty and splendor. The church is not supposed to be a “glory” of political power and luxury, which it was during Luther's lifetime.
The glory theologians of Rome are still with us. They glory in all three of these things.
Modern-day Romanists still apply their glory of reason to the Scriptures. I recently read a comment from a Romanist who admitted Mary's perpetual virginity isn't explicitly taught in Scripture. "Tradition" has to be hoisted upon the Bible so implicit implications can be drawn from the text. Another Romanist posits the Bible is materially sufficient, in that every true doctrine must be in harmony with it. What makes a doctrine "true"? Why it's none other than what the Roman church says.
There is of course still the Romanist glory of works. But wait, they say those works they do are prompted by Christ, or done with the help of the Holy Spirit. Hogwash. They are a denial of the perfect work of Christ. Only perfect works are those that can be presented before God. There are no works that can be added to Christ's perfect work.
There is also glory in the Romanist church. The multitude of conversion stories "prove" how glorious the "home" of Rome is. The conversion stories glory in their ability to find the promise land here on earth, and how great and wonderful this earthly kingdom is.
Rome's apologists and defenders are still theologians of glory. They stand opposed to the foolishness of the cross, and actively work against God's kingdom. However well-meaning, they are ultimately deniers of the perfect work of Christ. All their websites, blogs, discussion boards, seminars, books, tracts, etc., are examples of the theology of glory. That's a foolish thing to say, I know. Don't we just see thing a bit differently than the Romanists? Consider me a fool. I would rather be thought a fool than to deny Christ's perfect work.