Poor people need religion because their lives are so miserable that they would not be productive members of society if they didn't think they were going to go to paradise when they die.
Religion can be a good thing in America. It gives a code of conduct to those who are not ethical or educated enough to govern themselves.
'Don't worry, if you work hard, follow the rules, and give 10% of your money to the church, you'll get yours. It might not be in this life, but you'll be rich and live in paradise, and always be happy'.
But religion is here for two purposes. Anthropologists say that we as humans need to believe that we will somehow 'live on' after we die. The thought of just dying, and not existing, is hard the on the psyche. Also, religion is used for control of the population.
I was a Christian for many years. The thing that got me was this- If God is all mighty and all powerful, then why do the majority of people have to burn in a pit of lava? That silly 'free-will' answer never floated with me. I certainly wasn't going to follow a God that wasn't strong enough to defeat the devil and protect his 'children'. Might as well be a truck driver in Iraq with the Virginia National Guard as my escort.
It was at the same I was learning more and more about evolution and biology in college. "Hmmm, God sure took a strange and complex route when he made humans. Look at that, we share 98% of our DNA with chimps. Hey wait a sec, why do humans have remnants of a tail, and primitive gill slits when we are a fetus?"
So I'm quite content with the majority of the U.S. being religious. If it makes them happy (and they behave themselves), then its for the common good. Though I was a bit perturbed when GWB said "God told me to invade Iraq".