In my view, that's the central myth of liberal Protestantism, and wrong. While biblical literalism was not that strange for his age, it was still a move aimed backwards not forwards, it included resurrecting the darkest Dark Ages in form of religious persecution and (real) witch hunts (which, contrary to popular wisdom, were worst not in the Middle Age), anti-Jewish pogroms (Luther became a rather crude anti-semite in his old age), and establishment of opressive theocratic communities (Calvin's original wasn't any better than Salem). The learning process libral Protestants ascribe to Luther could really start only once religious absolutism led to disillusion and (unlike during all previous Western Christian internal religious wars) failed to achieve victory by arms.

_{*Lunatic*, n.
One whose delusions are out of fashion.}