Luther is never tired of urging that contemptuous treatment and rude chaff are among the most efficacious methods.
There was, he relates, a poor soothsayer, to whom the devil came in visible form, and offered great wealth provided that he would deny Christ and never more do penance.

The devil provided him with a crystal, by which he could foretell events, and thus become rich.

This he did; but Nemesis awaited him, for the devil deceived him one day, and caused him to denounce certain innocent persons as thieves.

In consequence, he was thrown into prison, where he revealed the compact that he had made, and called for a confessor.

The two chief forms in which the devil appeared were, according to Luther, those of a snake and a sheep.