Today one god is worshipped by two thirds of humanity. It is the culmination of an extraordinary story by which a single deity emerged from a pantheon of thousands in the crucible of religious ideas that was the ancient Middle East. In this episode we trace the birth, development and explosion of the religion of Abraham and Moses, from its very beginnings in Judaism to its triumph as Christianity within the Roman Empire. We also look at the earliest form of monotheism, as devised by Akhenaten in ancient Egypt.