Biography of Martin Luther, the 16th-century priest who led the Christian Reformation and opened up new possibilities in exploration of faith. The film begins with his vow to become a monk, and continues through his struggles to reconcile his desire for sanctification with his increasing abhorrence of the corruption and hypocrisy pervading the Church's hierarchy. He is ultimately charged with heresy and must confront the ruling cardinals and princes, urging them to make the Scriptures available to the common believer and lead the Church toward faith through justice and righteousness.