The Screwtape Letters
The Screwtape Letters (1942) is a novel by C.S. Lewis which contains 31 letters from a senior demon called Screwtape to a junior tempter called Wormwood. In the letters, Screwtape gives Wormwood advice as how to tempt his "patient" and keep him from following God's persuasion. Wormwood fails to bring suitable results. The patient becomes a Christian, has a revival, and dies in a bomb explosion and goes to heaven.
- Tempters, according to Lewis, have two motives: the first is fear of punishment, the second a hunger to consume or dominate other beings. On the other hand, the goal of the Creator is to woo us unto himself or to transform us through his love from "tools into servants and servants into sons."
The book is a marvel of perception about human nature and Christian ethics.
Lewis dedicated the book to J.R.R. Tolkien, his friend and fellow novelist.  In some versions of this book, at the end, there is an addendum called Screwtape proposes a toast. In it, Screwtape gives advice to some graduating devils on the state of the battle against "the Enemy"(God). He proposes a toast to "Principal Slubglob and the College!"