The Screwtape Letters
Wormwood, a demon apprentice, has been given his first earthly assignment: to secure the damnation of a a young man who's just become a Christian. He seeks the advice of an experienced devil, his Uncle Screwtape. Their correspondence discloses the psychology of temptation from the other side. This book gives invaluable insights on temptation, pride, the power of prayer, and the ultimate victory of faith over the forces evil.