But god was something made up by people in the first place! As mentioned higher up in the comments, people use to think the earth was the center of the universe, which was a theory and belief spread by people. God is the same way- someone suggested the idea of this deity, and many just accepted it as truth.
It was a follower-leader situation. Other things made up by humans have also been accepted as truth, such as the fact that the earth’s core is solid iron. But there is no proof to go with that conjecture, not the conjecture of the deity theory. I accept the idea of a core as a possibility, because we have some evidence to go along with it, but I don’t accept it as absolute truth because we have no absolute proof. God was man made and we have NO evidence of his existence, so I do not accept the idea of a god as truth. I prefer to know what exactly I’m believing in before I choose to believe it.