The best book I've ever read has got to be "Screwtape Letters" by CS Lewis. I'd put it in the category of "pretty much mandatory" reading for all Christians. The book is basically a conversation between an elder demon and a younger upstart regarding how best to win the soul of the young demon's "patient". If you hate to read, or if you just enjoy audio books, then I thoroughly recommend the 'focus on the family' audio version. I've been through it at least a half dozen times.
Question: If you could have world class skill in any one activity, what would it be? (Example: I might choose to be able to surf at the level of the top pros in the world.) I don't mean some super power like invisibility or time travel. I mean something that real people actually do like pole vaulting or violin or computer programming.