By certain laws of mysticism, deities can come into being with enough belief who in turn affects out world. In this sense, belief is extremely dangerous, and we do not know its full effect on causality i.e. time. This means every single considerable religion (and even cult) actually have a real god, and in some sense every single origin is simultaneously true (and as the religion dies the opposite would happen). At the same time gods are just common occurrences in the mystic, and all the gods popping into existence though out history combined would have a higher count than the current population. Luckily Humans are not able to affect things on a grander scale. I highly doubt any known deities is the literally godhead as no book or lore have demonstrated what I would consider omnipotent.