Who's to say God isn't exactly the same? He just happened to win out in the end, with a large portion of the entire planet's population believing in him, as opposed to only a few (relatively) low population countries believing in the older gods even at the height of their power.
Considering that they were
around first, at least as far as anyone knows (I think Judiasm only goes back to about 1800 BC or so, and only came about because Abraham was tired of all the pagan gods running around at the time), it's a pretty safe bet to back.
Honestly, reality itself seems to be all about the power of belief. There's simply no way to rectify all the different creation myths, especially those that predate the Christian one by millennia
. This episode alone demonstrated that Mount Olympus was real, that both the titans and Greek gods were real, and that they had origins pretty much on par with what mythology states. Which means they, too, ''created the world'' in a way that contradicts what the Bible says.
In the end, I just have to assume that whichever mythology is winning at the time is the "true" story as reality twists and contorts itself to make it true. Should science and reason ever replace religion in the setting, I'd bet a million bucks that it really was a random Big Bang that created the universe, not God.
At least until another theory or belief system takes hold, anyway.