There are no "hard questions" these books will cause to be asked of Christians. Well, except for "how the hell could these Kooks have attracted anyone to believe in this gibberish?"
Pride.
"You are part of a special and select group. You are better then they because you are a trapped divinity. We will teach you the secrets known only to a select few..."
Bah! It's the oldest con in the world and hasn't changed one whit since it was invented. Yet still people fall for it.