I also am an "Athiest" of sorts. I personally believe there is more proof that we were put here by an alien race as kinda like a "alien ant farm"....(Hmmm I wonder where they got that name) to see if we could thrive and survive.
I also believe that if you think about it, there are a lot of parallels to my thinking. The alien race that put us here could be construed as "God". I mean they ARE watching over us after all. I mean we have even shot down a few...
I also believe that we go back to the mother planet when it's all said and done, only to be replanted at a later date.
I personally think this is a better explanation, not to mention more proof of plausability, than the depiction of some old grey haired guy in a white mu-mu living in the clouds.
So. If you throw a cat out of a car window, is it considered "kitty litter"?