You're statement about "overwhelmingly obvious" is stated so strongly that I have no doubt that you do, in fact, believe in God. Ergo, why do you demand proof?
Just so you know, I'm agnostic and vaguely spiritual at best (worst?), so I'm not trying to proselytize here - just looking at the logic of your statement.
[ADDED] Remag, I see your additional details and I'm actually very interested in the argument. As you've added the point that you are agnostic, as am I, I would only say further to you that as far as I'm concerned, "if" there's a God, then God is a benevolent god and isn't keeping score - I just don't believe that a God, if there is one, would bother creating the cosmos, the Earth, and all life just to waste time... he/she/it would do so with a lightness of mood rather than a blackness of heart. And this means, for better of worse, that there is no segregated (i.e. heaven v. hell) afterlife, if there's an afterlife at all.
I just hope that I can live a life that is benevolent in intent, spirit, purpose, and manifestation - in other words, I hope I can live with civility (my agnostic version of "grace").
I realize this sounds awfully convenient to some folks, especially the bible-thumpers - but ya know what? It's my NON-religious view of living that makes living to be "good" or "civil" and with "purpose" even more of a challenge than it is for those who seek a spoon-fed, packaged solution! I'd rather be as I am than follow some scriptural line of thought that, more often than not, has lead to violent conflagration over the millenia in the very name of "God" and/or "salvation."