Kinda hard to put any hard evidence for or against the idea of a god since you can't experiment to see if your right. The people claiming to have seen heaven in near death experiences can also be our brain releasing endorphins so we'll see what we want to see.
Btw... I wonder how the notions that god created us in his image, his glory and that we're the chosen ones would be affected if we encountered an alien race more advanced than us and that didn't look like us. There are a few things like that which would make for quite interesting theological consequences.
