It's funny when I read people saying science, with all its hypothesis and things we arent so sure about, shows the existence of god, science doesn't have all the answers, and surely never will... But I think everything can be proven by logically, it's just that we don't have enough knowledge to do so. As mortal humans we surely never will.
I personally think the concept of god is a refuge for human fear. Think about it, what were the gods? In ancient Egypt gods and goddesses of rivers, floods, rain, i.e. unexplained phenomenons, fear it was. In the middle-ages, unexplained facts and events such as madness or sudden "healing"(now sometimes explained by science), fear of the unknown, again. And Nowadays, the mystery of the universe, maybe far too complex for any human brain, fear of death, of being mortal.
That's god for me.
I also think if I had to believe in any god, it would actually be gods. I'd be a polytheist, it's funnier and makes better stories, doesn't it?