i've said this so many times before: aliens are more likely than god. but, that's not just a reflection on the likelihood of our origins, it's an analysis of religion, itself. if you follow the line of reasoning forward, it actually brings up the same question that you hear so often in challenging the religious stories: why doesn't god talk to us anymore?
where are the aliens, anyways?
i want to be clear about what i'm suggesting, first. there's a constant in our religious mythology, across generations, that god came from the sky. you can trace this in the indo-european language and across comparative religion, as well. we have this idea of the skyfather that is really almost universal in our religious myths, and that also extends to non-indo-european religions. everywhere you go, you have the father in the sky and the mother in the earth. is there something to this? well, it's embedded in the mythology. every culture has these stories of beings descending from the sky, and of humans ascending to the heavens.
a rank cynic would discard it as nonsense, but a scientist would seek a naturalistic explanation. if there are aliens in the universe, they are no doubt biologically alive entities that move through the universe in obedience to the laws of physics. that is, aliens are not a supernatural phenomenon but are rather a naturalistic one. so, one way to offer a naturalistic explanation for religion would be the suggestion of extraterrestrial contact, you'd just need to find some evidence for it in order to prove it.
i'll let you discard this as a hypothesis once the fossil record is complete. in the mean time, i'd support some active archaeological work seeking alien artifacts.
but, why don't they come here anymore, then?
maybe they're dead.