Which 1955 C.S. Lewis book explains Christianity through letters from a senior demon to a junior tempter?

The Screwtape Letters is C.S. Lewis’s 1955 book of advice from a senior demon to a junior tempter.

The book is structured as a series of letters written by Screwtape, an experienced demon, to his inexperienced nephew Wormwood. Screwtape offers guidance on how to tempt a human being and prevent that person from developing a relationship with God.

Lewis uses the inverted viewpoint to expose habits such as distraction, vanity, resentment, self-deception, and spiritual complacency. The letters are satirical rather than a conventional narrative, and the demonic terminology allows Lewis to discuss Christian moral psychology indirectly.

The work first appeared in serialized form in the Anglican newspaper The Guardian before being collected as a book in 1942; a revised American edition appeared in 1943. Thus, the commonly associated 1955 date is not the original publication date, making publication history an important point of comparison.