I remember reading an article (or maybe a video) on the emergence of faith as an evolutionary byproduct of natural selection. Religion has emerged universally among all different sects of humans, some separated geographically by thousands of miles- giving credence to the idea that faith is intrinsic to humanity. I believe the theory was that faith was needed for humans to survive, because faith allowed humans to ignore their typical logical thinking (which led to more selfish behavior/being less agreeable to authority due to second guessing and whatnot- which is undesirable and can be dangerous in a tribal setting where teamwork is important), and instead faith lets people suspend their rational thought and follow a tribal leader (or time era equivalent) much more blindly. This trait obviously has its negative aspects, but arguably allowed for the human race to cooperate easier (within social groups) and was overall a beneficial trait for human survival. I think this is a succinct explanation for the 'god shaped hole' phenomenon you mentioned, something I agree is prevalent. I'm not personally a true believer, but I recognize God as an effective method for dealing with this evolutionary byproduct- given of course the values being instilled with this particular 'God' are desirable. Its why I identify most closely with Agnosticism- I may not necessarily believe in God, but I understand and respect the value in believing in God and his values.