C.S. Lewis’s The Screwtape Letters was published in 1942. The book is structured as a series of letters from Screwtape, an experienced demon, to his inexperienced nephew Wormwood.
Screwtape’s correspondence offers inverted advice about how to tempt a human being away from faith, virtue, and attention to spiritual reality. Lewis uses the demonic viewpoint satirically: readers are expected to recognize that the advice is corrupt even when it describes ordinary human weaknesses.
The work first appeared during the Second World War, when Lewis was already becoming known for Christian broadcasts and essays. It remains one of his most widely read religious books, alongside Mere Christianity and The Problem of Pain.
The book is sometimes mistaken for a conventional fantasy novel because of its supernatural characters. Its form is closer to a satirical theological fiction made from letters, and its narrator is deliberately unreliable and morally inverted.