You have had a discussion with Erasmus about the (un)free will. Is that such an important issue?

Luther:

You bet! Erasmus went at least to the heart of it. He has not bothered me with side issues such as the pope, purgatory, indulgences or other unimportant things. Everybody is talking about that, but that is actually pointless. Only he has seen the main point. I am very grateful to him for that.