In fact, that's the major push behind my philosophy. It really is only a model. Basically, I've spent most of my life as an aethist (mainly because I'm generally a science-based person - things need 'proof' - they need to be 'experimentally proven'. So I believed in Newton, but not in God, or Ygwh, or whatever the hell his name is.). I then decided that aethism wasn't really all that much fun either.
So I decided that I would believe in everything. Anything that anyone believes in, exist. So Chris (=the Christian God) sits at the same table as Zeus, and Ra, and Allah, and all of the Hindu gods, and Thor, and Mother Nature. At the table on the other side of the room we have Satan, Hades, Osiris... and Mother Nature. Also on the "good table" are Logic (created by those aethists who are so entrenched in science they honestly believe in Logic) and the Child god (who is a shape-changer - think Peter Pan, Santa Claus, Tooth Fairy, Mario, Bart Simpson and the Easter Bunny in one neat package).
The power of the gods is related directly to the number of believers and the strenth of their beliefs. So the Hindu gods are the most powerful, which is fair enough since polytheistic religions are by far the coolest out there. Chris is up there too. Unfortunately, in this time of Crusades II, the amount of power is also inversely proportional to the number of fanatics/fundementalists believing in the god. (Probably by an inverse square relationship, and we'll throw in a constant known as Eddings' Constant, for good measure)
Any aliens who are intelligent enough (or stupid enough, depending on personal opinion) to believe in Something also create 'whatever it is they believe in'.
Each of the gods has a personality, because otherwise it would all be far too boring, frankly - that's why conventional modern religions suck in my view. Can you tell I read a lot of fantasy?
Of course, we still need a Supreme Being. So Karma steps up to the plate. Karma isn't ACTUALLY a Being. Or maybe It's THE Being. Anyway, It's an unseen Force that has a sense of humour. It's still just Karma as people know It, though. It still balances your "good" acts against some Scales and rewards or penalises you as It "sees" fit. But It will also reward you before the event, and punish you later if it turns out you don't deserve what It gave you.
So these days, when certain Fundementalists I know ask if I believe in the Christian God, I reply, 'Yeah, Chris is a legend.' And I'm deadly serious; Chris IS a good bloke - he's just not the 'be all and smite all'.
NB - I apologise for the lack of decent coding - I'm new. Also, the informality is an issue which is on the agenda to be fixed.