The Screwtape Letters
It's the fun game of trying to imitate or ridicule the evil One, as a way to getting into his mind and understanding how rotten and perverted his thinking must be. Here C.S.Lewis plays the not so funny role of a Senior evil spirit who tutors a rather clumsy junior one through the art of misleading a London chap away from the path to the Father Above, and to bring him as food to the Father Below.
It's nothing but that gig, well exploited, though. The author in the appendix admits that he could have gone on and on but that the point was clear and needed no more samples; to have continued would have possibly been outdoing the purpose of the book, which is to make us readers aware of the reality and danger of evil, as dangerous and evil as the other side: God's true love represented in His Son Jesus. So this is fun with a purpose; gone the purpose, gone the joke.
I like Lewis's wit and humility to express ideas that are harder to express than to understand. Our peer-pressured society, politically-correct dumb world has carried us to this scenario -described comically in the book. The advice this expert evil spirit gives is just what Europe has told us since WWII the PC social sermons:
“I gather that the middle-aged married couple who called at his office are just the sort of people we want him to know -rich, smart, superficially intellectual, and brightly skeptical about everything in the world. I gather they are even pacifist, not on moral grounds but from an ingrained habit of belittling anything that concerns the great mass of their fellow men and from a dash of purely fashionable and literary communism. This is excellent. And you seem to have made good use of his social, sexual, and intellectual vanity.”