Well interestingly enough, Mt. Sinai is one the largest sources for naturally grown shrooms.
I'm not saying he found God, but a bush on fire sounds a lot like a bush that sunlight is reflecting off of while you're on shrooms. At least I can say that a similar experience happened to me, so I'm not going to rule out the occasional use of hallucinogens in religion. Especially when talking about Native American (both South and North America) cultures. The Aztecs, as a right of passage into manhood, would eat datura regularly. Which explains the fanatic heavily rhythmic dancing, just look at a rave in our times to see the simple connection. People fucked up on all sorts of drugs going to see very heavily rhythmic music (dubstep and drum and bass being two of the better examples).
I'm not saying that all religion or any religion had something to do with hallucinogens, I'm just saying that the possibility is out there. If you take offense to the idea of hallucinogens being a cause for religion, please just say so, and say in a way that does not target another member on this board. You have very interesting things to say, and I would like to hear them, but the problem with forum chats, especially this one, is that people try as hard as they can to insult each other after the fourth page of an argument's origin.