Screwtape Revisited

I've always heard of The Screwtape Letters from C.S. Lewis and so far have never gotten the proverbial "round tuit." Amazon's editorial review describes the book as:

"... the instructional correspondence between a senior demon, Screwtape, and his wannabe diabolical nephew Wormwood. As mentor, Screwtape coaches Wormwood in the finer points, tempting his "patient" away from God.

"Each letter is a masterpiece of reverse theology, giving the reader an inside look at the thinking and means of temptation. Tempters, according to Lewis, have two motives: the first is fear of punishment, the second a hunger to consume or dominate other beings."