I believe in God, but I don't belong to an organized religion.
It pizzes me off when people claim to know exactly what God is thinking, or especially when they say they're going to heaven and everyone else is going to hell. I think spirituality shouldn't be about judgmentality or self-righteousness.
When I was a kid, my family went to a Lutheran church for a while. One day after Sunday school, I came back to the regular service and found a guest preacher talking about Job or about the persecution of early Christians, I can't remember which. He had two kids standing next to him. He talked about how his enemies put his son's eye out, and had the boy cover his eye with his hand. And then he said his enemies cut out his daughter's tongue, and had the girl cover her mouth with her hand. I was thinking, "Is this what religion is about? Child mutilation? What if someone wants to cut out my eye or chop out my tongue?"