You sound like you want to short-circuit any debate and hear an atheist say what you desperately want them to say: namely that we all secretly know the Christian God exists, and that for all the bluster we all secretly fear him. I can't speak for anybody else, but I think that its very unlikely that the Christian God exists.
However, I was raised for the first ten years of my life going to church, and the idea of the Christian God is probably seated pretty deep in my sense of self somewhere. Although unlikely, I can imagine in my dying seconds formulating some kind of prayer to the almighty - its possible, especially in stressful circumstances - but what would that prove? I think it indicates more a human fear of death and the unknown rather than the fact that the knowledge of a Christian God's existence is hidden within us all. After all - if I'd been raised as a lapsed Muslim then I could very well do the same thing to Allah.
PS your topics title had me really excited - I thought you'd crossed to the dark side.