Or, as frequently posited, “man created god.”
The reasonable reader will assume that I will equivocate, avoid the question or give a non-commited answer. That is wrong. I will give an answer, and furthermore, I’ll explain why it is the only reasonable position.
But first, a little digression, if you will. What is God? The frequent belief is the one I nick-name “the supernatural monster”. God is a powerful (perhaps all powerful) being, who does stuff. But what does supernatural mean? Does the God in this belief exert actual influence on the world? And what does “supernatural” mean, anyway? “Supernatual” creatures, in the sense of “things which violate the laws of physics as understood today”, might well exist — after all, a human being using nuclear power (which uses E=MC**2 to generate energy) would violate the laws of physics as understood by an earlier age. Does this make them Gods? Well, not in an important sense: though these might be powerful enough to rule us, they hold no moral authority. If such a creature says “do not murder”, or alternatively, “kill all adulterers”, it might have ways to enforce it — but might does not make right. There is no reason to assume such a being is more moral than us.
This leads to the reductionist position that seems eminently inescapable for us: God is the difference between right and wrong. As such, God exists if right and wrong exist. Asking which came first, God or man, is like asking about the chicken and the egg. Chickens cannot exist without eggs, and vice-versa. Likewish, human society cannot exist without the concepts of right and wrong — and right and wrong cannot exist without human society to hold them as ideal. God created man, because man is defined by his belief in morality — morality is what makes large societies of unrelated individuals possible, and such societies are what defines “human” (and not membership in the species homo sapiens, as we see when we talk of people “losing their humanity”).
God created man, *and* man created God.