(extracted from bs from a conversation with my cousin a-)
In the end, in my view, religion is primarily a set of formal rules we follow to avoid the hobbseian state of nature. Neal Stepheson's novel Snowcrash sees humans as computers, blindly following rules (without being conscious of it), and things like culture/religion as computer programs (which are in essence just rules), that evolve to solve the nasty, short and brutish prisoner's dilemma/tragedy of commons we call the game of life. dawkins called them memes, a concept as fundamental nowadays to cultural anthropologists it seems as genes are to biologists.
But christianity (or more specifically post-enlightenment protestantism) is a step beyond, because instead of mere rules, it advocates meta-rules. don't blindly follow rules like don't work on the sabbath, or don't eat pork, or don't eat cows, or eye for an eye, but instead try to understand what god wants, (meta-rules). This is the faculty of reason that descartes and kant were so infatuated with. Reason with a capital R.
sorry, that was a random dump, but nice sometimes to synthesize all the various bits of philosophy I read in grad school (even sci-fi Stephenson was read and assigned for multiple classes).