Which C.S. Lewis book presents Christianity through letters written by the demon Screwtape?

The Screwtape Letters presents Christianity through letters written by the demon Screwtape.

Published in book form in 1942, the work is structured as correspondence from Screwtape, a senior demon, to his inexperienced nephew Wormwood. Screwtape offers advice on tempting a human known only as “the Patient.”

Lewis uses the unusual perspective to discuss pride, distraction, resentment, fear, and other habits that he believed could damage a person’s spiritual life. The satire works by having a demon describe harmful behavior as if it were sensible professional guidance.

The book is not a conventional narrative with a human hero and a continuous plot. Its epistolary form means that each chapter is a separate letter, although the letters together trace the Patient’s spiritual choices. Lewis later added “Screwtape Proposes a Toast,” which was published separately before being included with the letters in many editions.