I disagree. I think the "ingrained" idea that there is a supreme being and creator is inborn, and placed there by said creator. This is why people groups without outside influence typically have some system of belief in some type of supreme being. This is why religion hasn't been, and never will be eliminated.
You think it is more comfortable for a Christian to contemplate an afterlife than just an end? To consider that people will end up in hell? That is an uncomfortable thought, to say the least. Do you think it is easier to live knowing there are impossible standards that cannot be met on your own? You think that is easier and more comforting than living for your own self interest and just comparing yourself to other humans?
No.
If Christianity is false, then I do not want to live under the assumption that all of the things it entails are true. I would much rather believe that in the end we rot. THAT is a comforting thought. But believeng, as I do, that Christianity is true, I choose to live according to it. Not to get pats on the head, but because I think it is truth.