The Screwtape Letters by C.S. Lewis

The Screwtape Letters is a Christian apologetic novel by C. S. Lewis. It is written in a satirical, epistolary style and while it is fictional in format, the plot and characters are used to address Christian theological issues, primarily those to do with temptation and resistance to it. First published in February 1942, the story takes the form of a series of letters from a senior Demon Screwtape to his nephew Wormwood, a Junior Tempter. The uncle's mentorship pertains to the nephew's responsibility for securing the damnation of a British man known only as "the Patient".