Zeus and the other gods of shining Olympus were in reality divine only by popular consent.
These experiences were provided by the mysteries, religions that flourished particularly during the Hellenistic period and were secretly practiced by groups of adherents who decided, through personal choice, to be initiated.
Over the course of time Olympian luster diminished in favor of religious experiences more immediate to the concerns of people living in an increasingly cosmopolitan Ancient world.
Zeus and the other gods of shining Olympus were in reality divine only by popular consent