The most underrated teaching of Luther is that the Christian is a human being, and ought not rebel against being a human being. We are not only permitted to eat normal food and get married and hold civic office and pursue things we are passionate about, we are *encouraged* to do so by the God who loves us. In other words, Christianity does not require the abolition of the human, but a reformation of it.
This went against the quasi-buddhist rebellion the Church had been staging against God's vision for humanity for nearly a thousand years, where the height of righteousness was conceived of as starving to death in a cave and repeating prayers until your neural pathways calcified.
Lutherans so often forget this that entire denominational institutions ape Rome ad nauseam. It is as though they heard Luther teach about the Biblical conception of man and responded with "So you're saying we should be statues, right? Because we can *totally* do that, Doc."