The interesting thing about gambling on the supernatural is that the supernatural, by definition, has no objective, reality-based constraints. As soon as you can objectively measure and/or test something, and can determine whether or not it is likely to be true, it ceases to be properly supernatural, and becomes a question that can and should be answered through the use of the scientific method. Stick to the supernatural, and all bets are equally baseless.
For example, let’s suppose that there exists a supernatural predator who preys on the spirits of the gullible and incautious. Such a predator might groom his prey for the harvest, much as the American farmer fattens his turkey for Thanksgiving. He could manifest himself as a god, and attempt to lure believers to himself by various apparent (or genuine) miracles, and a pretense of spreading love, mercy and forgiveness. In the afterlife, anyone who sincerely believes in this god becomes god’s lunch for all eternity, or for at least as long as it takes the god to slowly gnaw away at your soul and devour it.
I’m not saying that any such god exists, but if we’re going to assume the reality of the supernatural, he’s at least as likely as the kind of god who would genuinely save you. (Hey, maybe he does save you—for a snack!) But such a callous, carnivorous, exploitative god would seem to fit the available evidence better than the loving, almighty Heavenly Father does. Plus it would explain why he seems to hate skeptics so much. They’re not only unfit for divine consumption, but they spoil others as well.
We can’t know whether God is a deceitful predator luring believers to their eternal doom. But if He is, and you trust in him, you’ve just made the worst mistake of your entire existence. Isn’t it safer not to believe in any god?