The Psychological Need For Certainty

"Agnosticism is something that doesn’t come easy to us. In fact, this is compounded by research that shows that people with more adamant and certain beliefs – think fundamentalist Christians and militant atheists – appear to be happier than those with more wavering beliefs. Certainty does make us happier."

Note that atheists AND the religious with firmly held beliefs are the happiest.  To clarify, I, and most atheists I know, realize that absolute certainty is elusive.  We are just certain that it is most probable that there is no interventionist god.

Note also that probability supports naturalism as the explanation for reality rather than anything supernatural:

The cause of lightning was once thought to be God’s wrath, but turned out to be the unintelligent outcome of mindless natural forces. We once thought an intelligent being must have arranged and maintained the amazingly ordered motions of the solar system, but now we know it’s all the inevitable outcome of mindless natural forces. Disease was once thought to be the mischief of supernatural demons, but now we know that tiny, unintelligent organisms are the cause, which reproduce and infect us according to mindless natural forces. In case after case, without exception, the trend has been to find that purely natural causes underlie any phenomena. Not once has the cause of anything turned out to really be God’s wrath or intelligent meddling, or demonic mischief, or anything supernatural at all. The collective weight of these observations is enormous: supernaturalism has been tested at least a million times and has always lost; naturalism has been tested at least a million times and has always won. A horse that runs a million races and never loses is about to run yet another race with a horse that has lost every single one of the million races it has run. Which horse should we bet on? The answer is obvious.  ~ Richard Carrier

So, given the above, why would one believe in the supernatural?