What is the name of C.S. Lewis’s Christian allegory written as letters from a demon?

C.S. Lewis’s Christian allegory written as letters from a demon is The Screwtape Letters.

Published in 1942, The Screwtape Letters consists of correspondence from Screwtape, a senior demon, to his inexperienced nephew Wormwood. The advice concerns temptation, distraction, pride, resentment and the ways people can be diverted from moral and spiritual growth.

Lewis uses an inverted perspective: the demonic characters describe good as if it were dangerous and evil as if it were professional success. This reversal creates both satire and theological commentary. The book’s format is epistolary, meaning it is presented through letters.

The work is sometimes confused with The Great Divorce, another Lewis book about Christian ideas, but that later title is a fictional journey rather than a demon’s correspondence.