How the "idea" [not a concept] of God emerged onto human consciousness is due to an inevitable unavoidable existential crisis of inevitable mortality so terribly painful [subliminally] and cannot be resolved by a human at all.
Thus it is very natural, the mind conjured up an idea of an omnipotent, omniscient, omnipresent and omni-whatever, a Being [God] than which no greater can be idealized to resolve the inevitable unavoidable existential crisis.
Beliefs in something as real [even in fact false] do work [note placebos] and the belief in an illusory idea of God does work to resolve the unavoidable existential crisis inherently within ALL humans.
Because, the above belief of a God [even in fact false] works to relieve the terrible existential crisis, pains and Angst, theists will cling to it like there is no tomorrow, as to give it up would bring back terrible sufferings and Angst. This is why so many theists [this is glaringly evident] will not hesitate to kill whoever threatened their belief in a God.
Thus whenever the question of God is raised, one has to take note of the reality of psychology within the minds of theists as explained above.