The Screwtape Letters: How a Senior Devil Instructs a Junior Devil in the Art of Temptation by C. S. Lewis

C. S. Lewis was one of the greatest Christian Writers of our age. His "Screwtape Letters" still stirs considerable controversy. He wrote from the perspective of a devil giving advice to another devil in how to tempt a Christian. In doing so, he reveals to us how we let evil into our own lives. Lewis's work has influenced three generations of Christian thinkers and will continue to be a seminal Christian work.