The Arab world has been held back by religion, so clearly, not all religion is good for empires or civilizations.
Yes, in the past, some "religious" codes of behavior (really, existing behavior which evolved and then got codified into religious values) was beneficial to some cultures. For example, monogamy decreases the likelihood of STD and increases chances for your offspring to survive.
But the fact that human beings have a neurological tendency to experience "God" (clearly explained by modern neuroscience, right down to experiments that can simulate it for anyone) does not mean that we should be bound to this behavior. Nor does the requirement for *law and order* mean that we must submit to religious or mythological sources of authority. Our children can be raised on myth as Joseph Campbell has said, but they can also be "weaned" from it when they pass through adult hood. We tell our children lots of stories as kids: Santa Claus, Easter Bunny, Tooth Fairy. But they do not persist as behavior governing philosophies after adult hood. Why do we need to keep the big bad vengement god around who's going to burn you in Hell?
Humans also have a tendency towards tribalism, and there are many historical behaviors that may have served us in the ancient world, but do not fit into modern society today.
The Chinese have gone through 2 generations of enforced atheism and not suffered for it. They thrived on religions that are relatively agnostic (Taoism, Confuscism, Buddhism), do not have all powerful dieties. China had a huge secular civil service and bureaucracy when Christians in Europe were running around in furs and painting themselves blue. The emperor was about as close as you got to an all-powerful entity, but the emperor's power derived from army and elite, and he and the ruling elite were not beyond criticism (especially from Zen)
I think we've outgrown religion. A highly educated society doesn't need it to distinguish right from wrong.
BTW, I have a structured belief system. It doesn't require a deity. It consists of the golden rule (derivable from Game Theory), a respect for my place in the world and the fact that I need other people, and a general distaste for causing or seing pain in others (the latter of which turns out to be the largest reason why most people aren't violent) I don't commit evil acts because God will punish me (don't believe in the slightest, I'm a radical materialist, if you want to label my beliefs) I don't commit them because I don't like doing it, and I don't like the secular legal repercussions.
Perhaps this is too complicated for children, and they need simple "good" and "bad" rules. But they can get these rules by observing their parents behavior when young, or taught in school. Isn't secular punishment enough by parents or community leaders? Do children even understand what it means to burn in hell for eternity? Teenagers certainly show a very short term view of the future, and don't understand the repercussions of actions they take at a young age.
At the very least, if we were to discover that children need mythlogical stories when young to be taught codes of behavior, we can secularly devise such stories and synthesize them. They've gotta be better than a religion with 678 counts of violence:
http://www.skepticsannotatedbible.com/cruelty/long.html