Personally I don't know. How could you? What I believe is a different matter, and although I do not attatch myself to any particular sect of religion(**), I do believe in something. My opinion in religion is very different from what the typical "god-fearing man" man might come to believe, but I believe in Life. The very minute probability in us being here under these conditions by mere chance is a miracle in itself.
(However, I lean toward the idea of Buddhism, in particular toward Zen)
Perhaps there's no God behind this, and sure, if you roll a dice enough times you'll get the perfect 6 (ie, build enough planets over time, the universe will spawn a planet that we deem as life giving), but I've been given this chance and I'm going to live it as well as I can, including living as much as I can, but helping and giving. Sure, I don't give away everything I have (I'm saving to buy a Mac mini next month
) but I do try and go a step in the direction of making someone's day a little brighter when I can.
As for religion in itself I believe, as Lou said, it's a control device. I'm not saying religion is wrong (in it's ideas or implementation), but primarily it's good to have the world out there thinking "if I do something morally wrong I will be punished". Conversely however, there have been some attrocious deeds carried out in the name of religion.