Do Aliens Exist?

As we discussed in class it seems likely that aliens do exist simply because the universe is so vast that it would be more unlikely that there wasn't other life forms out there. It occurred to me that the only way that I think that someone could reasonably suggest that there were no other forms of life in the universe would be to give a religious reason and suggest that God simply did not make other forms of life. I am not saying that a religious person would say this, a person can easily believe in God and believe in the possibility of aliens. Rather I am suggesting that if you are not a religious person and believe that God had no hand whatsoever in the making of humanity it would be almost impossible to believe that aliens don't exist out there somewhere. Whether we will ever find them or be able to communicate with them is another question. I am one of those people who wants to believe that there are aliens out there, probably because I envision it like some sort of Star Trek episode where it all works out in the end and our intentions are always noble, but when i watched Avatar I thought that scenario was probally more likely. Money and greed for resources combined with our own inflated sense of self importance would not lead to an idillic relationship between us and our new alien 'friends.' If a sistuation like Avatar was ever to arise I wonder which conflict would be greater; conflict over money and resources or conflict over culture and religion?