Which C.S. Lewis book contains the famous allegory of a young man tempted by a senior demon?

The Screwtape Letters contains C.S. Lewis’s allegory of a young man tempted by a senior demon.

Published in book form in 1942, The Screwtape Letters is presented as a series of letters from Screwtape, an experienced demon, to his inexperienced nephew Wormwood. The younger demon is assigned to influence a human known only as “the Patient.” Lewis reverses the usual perspective of religious instruction by describing temptation from the imagined viewpoint of Hell.

The letters discuss distraction, vanity, resentment, social pressure, and misplaced priorities. Their satirical tone makes the book memorable, but Lewis intended the work as a serious examination of moral and spiritual habits rather than as a conventional fantasy adventure.

The book began as pieces written during the Second World War, including material first associated with The Guardian, an Anglican newspaper. Readers sometimes confuse it with The Great Divorce, another Lewis work using imaginative fiction to discuss theology. The Great Divorce instead centers on a fantastical journey from a gray afterlife toward heaven.