Isn't God Just a Projection of a Christian's Mind?

I think he is what keeps them in line. I mean, how many "good Christians" are there really? I would think a "good Christian" would not need the wrath of some unseen God to keep them from doing wrong. They should do the right or moral thing because they want to, not because they fear damnation or hell. Its all very silly and childish, in my opinion.