"I refuse to prove that I exist," says God, "for proof denies faith, and without faith, I am nothing."
"Oh," says man, "but the Babel fish is a dead give-away, isn't it? It proves You exist, and so therefore You don't."
"Oh, I hadn't thought of that," says God, who promptly vanishes in a puff of logic.
"Ah, that was easy," says man, and for an encore goes on to prove that black is white, and gets killed on the next zebra crossing.
Most leading theologians claim that this argument is a load of dingo's kidneys.