Hello, first of all I'd just like to say that it's so refreshing to read intelligent arguments about this subject rather than the stubborn abuse you usually find. I just wrote to recmommend a TV show you may enjoy though I expect you've already seen it, I'm recommending it just in case you haven't. It's called The Power of Myth and it features Joseph Campbell. It gives a nice insight into religeon looking from a mythological point of view.

Anyway if you've seen it that's cool, if you haven't I'd recommend you watch it.

The Power of Myth is indeed very interesting (I'm more familiar with the book than the TV show). It not only helps explain the origin of religion, it also says a lot about how we build stories that become an important part of our culture. Studying this and books like Brunvand's series on urban legends can go a long way toward explaining how a religion can arise and develop without anyone setting out to intentionally deceive. For atheists in particular, this may be very useful knowledge.