THERE is an old joke Norman Mailer is particularly fond of about a man who is complaining to God. The man whines: "You're not treating me fairly, God. Why not? Why don't you treat me fairly?"
"And the thunder comes down from heaven," Mailer said, anticipating the punch line with a grin. "And God says, `Because you bug me.' "
Mailer told the joke to help explain his own religious beliefs - and the God in his new book, "The Gospel According to the Son." "I've always been religious," he said. "I just have a God that's a little different from others. It's not because I'm special. It's just that it's the only thing that makes sense for me: the notion I have of an …