The primary driver of civilization is often misattributed to any number of things, including religion.

The truth is that the real explanation for civilization is the fact that when man's brain finally developed to the point where he was capable of grasping the force multiplier of cooperation, he for the most part left off the destruction of his enemies, and began to either rule over them or cooperate with them to accomplish things he could never have accomplished without their help.

That is to say, the comprehension that the division of labor would make himself more prosperous while making others so as well was the great civilizer.

Thus the great marauding hordes of yor settled in one place and became the government.