If There Is No God, Then Why Do So Many People Believe in God?

A reader recently asked me this question.

I was raised Catholic and even as a child I just couldn't believe that if there was a God who created the universe and, by extension, us, that He wouldn't expect us to use our brain to reason and learn was was real and unreal.  My major concern, I guess, is that so very many educated, intelligent, and respected people claim to believe.  Why do they believe when I don't?? What am I missing?  Or perhaps, what are they missing?  I'm reasonable intelligent but I just cannot reach the same conclusions as believers seem to reach.

I think this is a great question. Atheists throughout history have tried to explain religious belief by appealing to wish fulfillment, the influence of family and culture, the (alleged) irrationality or ignorance of theists, and so forth.

In my opinion, the best explanation comes from the cognitive science of religion: humans evolved a Hypersensitive Agency Detection Device (HADD). Most humans seem to be hard-wired to believe that agents explain various facts; this tendency seems to include all sorts of invisible agents, including God, gods, ghosts, and so forth. The advance of science has systematically reduced the need to invoke invisible agents, by providing naturalistic explanations for things previously explained by invisible agents.

ETA: Fixed a typo in an earlier version that referred to a “Hyperactive,” as opposed to a “Hypersensitive,” Agency Detection Device.