"And it came to pass that the Lord spake unto Moses, saying: Behold, I areveal unto you concerning this bheaven, and this cearth; dwrite the words which I speak. I am the Beginning and the End, the eAlmighty God; by mine fOnly Begotten I gcreated these things; yea, in the beginning I hcreated the iheaven, and the earth upon which thou standest."
"In the abeginning bGod ccreated the dheaven and the eearth. "
"And then the Lord said: Let us go down. And they went down at the beginning, and they, that is the aGods, borganized and formed the cheavens and the earth."
After choosing your Physics, the game rules by which your world will revolve around, it's time to venture into actually generating your world. Metaphysics. One thing is important, though. It's one thing to choose your physics. The Metaphysics is a whole entirely different thing altogether. Fortunately the next step is easy. This Article deals with Project Genesis.
You must decide upon the Gods of your world. Whether it is one, two, or many. Choosing the God or Gods of your World will have a definite impact on your World's mythology and how the world's inhabitants view the world and certain cosmic truths. Life and Death, Morality, Power of Choice, Magic, Psionics, and Philosophies are impacted. There are many examples of Fantasy worlds with a Pantheistic setup. Greyhawk, Dragonlance, Forgotten Realms, and many many others are Pantheist worlds. There are few examples of worlds with Monotheistic and Dualistic setups.
As for Galatea, I have chosen to stick with one God. This is so that I can have a myriad of religions, truths, and philosophies for the inhabitants of Galatea to choose to believe in. Having one God is also pretty much consistent with Real World physics (yes, you could Argue that Abraham accounted for many gods coming down and organizing the Earth, and you are right. And I totally agree with you, but . . . I have my reasons. :) ).
This One God, however, is not a He nor She. Rather, the One God is an It. From this one God sprang all Life, in order to Comprehend Itself more fully. So, it split a part of itself into an infinite amount of parts. And these parts are the spirits of all.
Planes of Existence
One thing should be mentioned here. Cosmic String Theory seems to support the fantastical notion of Planes of Existence. After all, Cosmic String Theorists claim that the universe is flat, and is part of an infinitely huge cosmic string of Energy. And that there are other Cosmic Strings that have other Universes.
You should choose the Planes of Existence as far as your world goes. Alternate realities exist on different Material planes or cosmic strings. You can even have planes of Heaven, Hell, and inbetween (the Great Wheel is a good example).
Next: Approaches in Project Genesis: Top Down, Ground Up, Continental, National.