I believe in a god simply because the alternative is too depressing. What if life was just a meaningless accident? If that's true, then the universe is just there - it's not there for us. The what's the point of even having a universe at all? It's all just meaningless, pointless suffering.

I prefer to think that God gives life context. It's like... If you think of god as a parent, and kids as all life, and the universe as a jungle gym.

The kids can play and be happy and be sad and make their games, and they can do so safely because their parent is right over there watching everything. (S)he won't interfere in the games, but when the games are all over, (s)he'll take you home, put bandaids on your bruises, and encourage you to go play tomorrow.

Without a parent there... The whole scene just becomes more sad.