Nothing like a standard narrative but not exactly a book of theology or morals, C.S. Lewis' The Screwtape Letters takes the concept of the proverbial devil on your shoulder and gives him an uncle who is much better at the job. A series of letters from experienced, crotchety Screwtape to woefully green Wormwood on the proper methods of human temptation comprises this insightful, and often wryly funny, epistolary novel. Certainly, like many of Lewis's works, Screwtape aims at a Christian audience, but the book contains wisdom for all manner of people regarding the darker side of human nature. While not light reading, The Screwtape Letters is a treat to read for its sarcastic, inverted perspective on the darker side of human nature. Also recommended is John Cleese's masterfully and hilariously narrated audiobook version.
Letters from the devil Screwtape to his less experienced nephew and apprentice Wormwood reveal a cunning plan for committing human souls to damnation, in an illuminating look at temptation, repentance, forgiveness, and grace. Reprint. 75,000 first printing.