While I was posting another thread, I considered a comment made that I read here at V under a thread on Islam: "What do we need Islam for?" (paraphrased)
Let's open it up a bit, beyond even "what do we need religion for," though that would be an interesting sidebar.
What's the overall purpose of religion?
If I had to pick one purpose in my life it might be to organize thoughts in a social setting around belief, faith and society. But I'm a Unitarian, and I realized that definition is more UU than anything else. And I admit my next definition I came up with is more than a bit cynical...
Seems to me the purpose of religion is to restrict our thinking, to prevent us from thinking out of the box. Sometimes this can be noble: like human sacrifices, sometimes NOT. But it does seem to me that religion, collectively, is intended to get us all on the same page... even force us to stay on that page. Not likely to ever happen, but an attempt. The claims that it's conveying what God, Allah or the Great Golem Beaver in the Sky really wants is a bit convenient, don't you think? Maybe true. Most likely, in most cases: not.
Essentially religion is much like any authoritarian form of rule: conform or else. These days it's most likely, at it's worst, to simply eject you from the group... though Jim Jones was not all that far in the past. Used to be if you didn't follow it would get you burned at the stake or your head cut off. That last one still prevails, to a certain extent.
Note: I am referring to collective group actions; not individuals who decide to kill a Gay because he offends their religious sensibilities. Not that I minimize how horrible those, and other, deeds are.
To those who believe: please understand I am not attacking your beliefs, whatever they be. I am referring to the purpose of organized religion.