Back in my agnostic days, there was a philosophical idea I bandied about, along with my UU comrades, that religion was basically superstition, but that it may have had some credible contribution to society in contributing moral order. The beliefs were relatively unimportant (reinforcing the UU tradition of letting everybody create their own theology) - it was the rituals that bound people together.
"Not so!" says Rodney Stark, author of For the Glory of God: How Monotheism Led to Reformations, Science, Witch-Hunts, and the End of Slavery, reviewed in Christianity Today by David Neff.
From the review:
"So, then," Stark concludes, "let us finally be done with the claim that religion is all about ritual. Gods are the fundamental feature of religions." This is a sociology of religion that takes seriously what people believe. Stark knows that beliefs have consequences. They can even change the course of history. And in the book's final sentence, Stark claims that in the ways he describes, "Western civilization really was God-given."