I do recommend Dr. G's Theology class to everyone who can take it. It was and still is one of my favorite grad classes. Likewise, I recommend eating his wife's cooking, very tasty!

Here are quotes from Reformed Lutheran Theologian Dietrich Bonhoeffer:

“It is a fatal misunderstanding of Luther’s action to suppose that his rediscovery of the gospel of pure grace offered a general dispensation from obedience to the command of Jesus, or that it was the great discovery of the Reformation that God’s forgiving grace automatically conferred upon the world both righteousness and holiness. On the contrary, for Luther the Christian’s worldy calling is sanctified only in so far as that calling registers the final, radical protest against the world. Only in so far as the Christian’s secular calling is exercised in the following of Jesus does it receive from the gospel new sanction and justification. It was not justification of sin, but justification of the sinner that drove Luther from the cloister back into the world. The grace he had received was costly grace. It was grace, for it was like water on parched ground, & forgiveness of all his sins. And it was costly, for, so far from dispensing him from good works, it meant that he must take the call to discipleship more seriously than ever before. It was grace because it cost so much, and it cost so much because it was grace. That was the secret of the gospel of the Reformation—the justification of the sinner.

Yet the outcome of the Reformation was the victory, not of Luther’s perception of grace in all its purity and costliness, but of the vigilant religious instinct of man for the place where grace is to be obtained at the cheapest price. Luther had said that grace alone can save; his followers took up his doctrine and repeated it word for word. But they left out its invariable corollary, the obligation of discipleship. The justification of the sinner in the world degenerated into justification of sin and the world. Costly grace was turned into cheap grace without discipleship. (Cost of Discipleship—pp. 49-50)

“Christianity without the living Christ is inevitably Christianity without discipleship, and Christianity without discipleship is always Christianity without Christ.” (pg. 59)