Ernie,if you are talking about "Social Darwinism" thats a pretty discredited science.
And there is no way of knowing that all successful societies ever have had religions, although the vast majority appear to have had some kind of religion. There is no evidence for ritualistic behaviour before the upper Paleolithic, by which time humanity had spread to most of the world, in some form or other.
Arguing from that point that religion is one of the vital ingredients of humanity's success is specious reasoning at best. You could just as well argue that religion is the side effect of human curiosity seeking to explain natural phenomena without a sufficiently developed theory of the world, and the power of narrativeon a species whose evolutionary advantages are a versatile and flexible brain, and a complex and efficent form of communication that includes abstract concepts and ideas.
That social cohesion that common origin stories among non-kin groups can bring about is potentially advantageous, as are taboos and mores handed down from a "higher authority". Pretty often religion is as much about maintaining and legitimising power as it is explaining the world, laying down ways to live with others etc.
It'd be interesting to think how christianity would be different if the Jews had been goat-herders, not shepherds. You lead sheep, goats have to be driven.