This Great Courses text is the best I have yet read for helping the reader to understand how religion functioned and why it mattered in the Ancient World. Most of the text focuses on the Graeco-Roman world, but there are also useful chapters on earlier religious practices. The importance of ancestor worship and the religious significance of legitimate bloodlines was also quite interesting as was the way that religion influenced the ways in which Julius Caesar and Augustus carried out their acquisitions of power. But mostly, Muller's text helps the reader to understand how different the world was in ancient times and why it is difficult for us to think in the ways the ancients did.