The Devil's Elixirs by E.T.A. Hoffmann is a novel that has overt religious themes, although the book is more similar to a Shakespearean-style narrative of good and evil. The setting is at a monastery, and the protagonist initially practices the life of a religious monk. However, he drinks the "devil's elixir," which catalyzes his regression back to human traits, such as lust and temptation. His stepbrother, the Count, represents evil, thus completing the theme of duality. The doppelgänger itself represents the protagonist's own inner demons, even though the doppelgänger was a separate external force.

There is a theme of repentance, but the author shows the frailties and weaknesses of human beings. The protagonist repents repeatedly, and yet his feelings of guilt do not stop him from fully shedding his devilish ways. When the woman he loves decides to become a nun, he has to fight temptations of lust. When the doppelgänger kills her, Medardus once again feels guilt and makes an act of repentance. However, it is hinted that even when he died, Medardus was still possessed by Satan, thus emphasizing the main theme of the book.