Religious belief is humankind's earliest science. Judaism, Christianity and Islam are young religions in historical terms, and came into existence after kings and emperors had more magnificently taken the place of tribal chiefs. The new religions therefore modelled their respective deities on kings with absolute powers.
But for tens of thousands of years beforehand people were fundamentally animistic, explaining the natural world by imputing agency to things - spirits or gods in the wind, in the thunder, in the rivers and sea.
As knowledge replaced these naiveties, so deities became more invisible, receding to mountain tops and then to the sky or the earth's depths. One can easily see how it was in the interests of priesthoods, most of which were hereditary, to keep these myths alive.
With such a view of religion - as ancient superstition, as a primitive form of explanation of the world sophisticated into mythology - it is hard for non-religious folk to take it seriously, and equally hard for them to accept the claim of religious folk to a disproportionate say in running society.
An excerpt from the article Believers Are Away With The Fairies by AC Grayling.