Wow. Heated and interesting discussion.
While I suppose that in the end I see "God(s)" as kind of a talisman (an important one for many people, and I support that belief for those who wish it), I am currently in the middle of my own spiritual investigation and for now do postulate a belief in God.
My reasoning really begins with Descartes' well-known phrase "Cogito Ergo sum" or "I think, therefore I am."
I know that Descartes reasoned up to God using this as his starting point, but I wished to start anew with my own reasoning. Really, because I've never gotten around to reading his reasoning, and besides, it was too much fun doing it myself. In the end, it is also my investigation, starting from myself (my own ability to doubt all except that I doubt).
Since I know that I exist at least subjectively (there are--however unlikely--reasons to doubt anything besides), I can divide my existence into two worlds: my known subjective perspective, and the assumed objective world. I may as well assume the objective world exists, since 1) my subjective mind is fed by my senses, and they are the only instruments available to me to detect my world (even if given to me by an evil genius), and 2) even if I am a "brain in a vat," there is still an external world to that vat.
My subjective mind may indeed be seperate from my body, because if all the material of my body were copied (DNA, memories, etc.), I could still not look at each copy through the same subjective mind (or, at least, I take that as highly absurd).
Now, since I have established that I exist in two worlds--the objective and subjective--I can say that one would not exist without the other. This does go back to the if-a-tree-falls axiom, in that, if I did not exist would the objective world exist? It would, for other subjective minds, if I may assume they exist (which I could, since Descartes could also doubt everything but his thinking, showing the possibility of outside subjectivity). But imagine that I was the only subjective mind left in existence. If I die, does then the objective world cease to exist?
It seems like an impossible answer, since no one would be around to see if it fades out of existence. But that's precisely the point: no one is around to subjectively view its existence, so it therefore does not exist (or should I say, may as well not exist? Really, I see them as one in the same at the moment). I also want to say that the opposite is true: without the objective, the subjective would not exist, but I see that as rather obvious.
So if the objective world exists, then life is crucial to its existence. Unless there is a subjective entity seperate of life.
Life is a rather delicate thing, and it can be imagined that the universe could be void of it at times (unless it is infinite, but I'm not sure I want to go there now). It cannot be void of life, because in order to create new life through whatever means it uses (evolution?) it needs to exist. If the origin of subjective perspective (consciousness) were seperate from the material universe, then it could sustain the existence of the material world through whatever changes it goes through, as well as act as the origin of organic consciousness.
Thus, I take the long--but personally needed in order to prove it to myself--way to panentheism (or some form of it. Would this God necessarily have to the "moving force" behind the universe, or simply a conscious observer?). I am forever in discovery, since I am but a subjective mind in a world of limitless possibilities, but this works for me now.
But that's just my perspective.