“Lord Jesus, it is for thee that I patiently endure this cruel death. I pray thee to have mercy on my enemies.” Early in his monastic career, Martin Luther, rummaging through the stacks of a library, happened upon a volume of sermons by Jan Hus, the Bohemian who had been condemned as a heretic. “I was overwhelmed with astonishment,” Luther later wrote. “I could not understand for what cause they had burnt so great a man, who explained the Scriptures