So what are we looking at here? Whatever we see of course. The person of faith knows God because he knows Him but can make the mistake that proof of a kind satisfying to a skeptic can exist. This is because it is obvious to him that God exists and should be obvious to everybody. He sees the proof in everything but the proof that he sees isn't scientific evidence but conviction that arises our of feeling. The certainty that God exists corresponds to an inner feeling a recognition that believing in God is a great place to be. He is happier than non believers and lives longer, but probably at least in part for social reasons he has a community of believers, most likely, with which he can commune. Communism is another thing you can get quite certain about because of the good feelings it can bring.
Unfortunately, because the believer thinks that the source of his belief lies in what he believes, he may miss the fact that the reason he believes is because of the state of being that belief creates. He knows that believing is more satisfying than not and that's why he believes believing is better. But the result is that he can become a fanatic, thinking that the belief is what matters, not the state that belief puts him in, a state that others also have but based on different beliefs.
So the Atheist comes along and sees all the proof that the religious create and walks away shaking his head. This is nonsense, he proclaims, and it is, for the religious part. But because he feels nothing from his belief, he has nothing to protect or project. He has no gift to give except the satisfaction that he doesn't believe in nonsense and all the shit it creates, that he's not an insane holy warrior. He has rejected bridges altogether.
But beyond all this is the real purpose of religion, to help men find an 'ultimate' state of awareness, to be in the world but not of it, to not be attached to things, etc. This is something both the religious and non religious, I think, can easily miss that duality can be transcended creating a different state of being. This can happen with or without religion. It can happen through the mind or the body as well as the heart, but if the room that is opened is lacking love, then the room is empty. It's is the quality of the love that blooms when this state is entered that creates something deeper than the certainty of faith or doubt and it is love-knowing. It can't be proved but when it is taken as a theory illuminates a lot of things that make sense in no other way, in my opinion. The sense on inalienable rights, for example, makes sense in there is an inalienable truth to which those rights cohere. Everybody has a sense of justice, of fair play, because it is the image in which we were created. So even if no God exists, he still exists within us.