Luther has been criticized to have spent too much time dwelling on how sinful man is. This “preoccupation” with man’s corrupt nature is claimed (by critics) to be foreign to the teachings of Paul. Rather, they say, Paul was usually anxious to declare how blameless he was under the law. Now granted, Paul doesn’t mention the depravity all that much (apart from the ‘none righteous’ passage). And Luther seems to dwell greatly on human corruption in his writings. But there’s a difference between Paul’s writings and Luther’s writings. Paul is writing letters to fellow Christians, who are dealing with specific problems. Luther’s writings, on the other hand, are journal-type, theological ponderings. The depravity of man isn’t really an issue that one of Paul’s churches would have struggled with (hence, not much reference to it in Paul’s letters). It’s clear from Romans and other texts that Paul believes in the depravity of man—he just doesn’t talk much about it. Luther, who’s desire it was to write a systematic theology on this specific issue, spends a ton of time on it, because really the doctrine touches on every aspect of Christianity. For instance, if man were not totally depraved (as Luther expounds on at great length), one probably wouldn’t have to have faith in Christ alone—a major topic in Pauline theology. The depravity of man is such an important, basic, and essential truth to the Christian faith, that without a correct view of the natural state of man, one cannot fully comprehend the purpose of Christ’s death in history.