I wondered if there were people that were atheists that used to try to challenge the system and maybe mocked people that believed in Zues, Ra or any of the other gods of those time periods. And if they did, what kind of things would they say?
According to Lucretius the Greek philosopher Epicurus and his followers assumed gods to exist, yet have no effect on human life and no part in the creation of the world http://www.epicurus.info/etexts/PD.html
Edit: clarified sources.