If there's one way to get a thread rolling, it's title it "Christianity."
Anyone that says that there definitely is or is not a god, is an idiot. You can't prove that. Like many have mentioned, it's a faith on both sides. I prefer the "I don't know" religion.
Humans are far too stupid to know. We're more or less chimpanzees that have invented a variety of very advanced sticks.
Not to say that ritual and prayer, of any religion or personal belief, can't be helpful.
Prayer can be very good for the person praying. And if through prayer, that person helps someone else, it can be good for others too. "I'll be praying for you" seems more harmful than helpful. It's like, "Well it's in God's hands now! My work here is done." It can be a nice sentiment though.
I once heard the phrase "Prayer Warriors" and I thought, those must be the wussiest warriors and the face of the planet.
The best part of Christianity in many countries is not the religion itself, but the community that revolves around it. The people, the friendships.