Pragmatic function / source of efficacy of religion?

[Heretic.Ape.]

Some who are not religious are quick to dismiss spirituality etc as a whole as merely a widespread delusion of no value or even negative value.
But surely something that seems inherent in the majority of human psyche and behavior has some advantage that has assured it's emergence and perpetuation?

For instance, religion as we know it today finds its evolutionary roots in shamanism. shamanism is a universal phenomenon among hunter/gatherer societies. These societies claim to gain a great deal of practical knowledge and "power" (healing, finding out where animals for hunting will be, etc) from using various means to cross over into the "spirit world" and communicate with "ancestors" or other incorporeal beings. (I generalize here).

For such similar systems to evolve independently scattered in tribes all across the globe having no contact with one another and living in conditions in which most components of culture have important survival functions implies to my mind that there must be some merit to it's efficacy.

The basic formula has not changed. For example in Christianity a person uses prayer and fasting to communicate with an incorporeal entity to beseech it for knowledge and power over aspects of their lives. To it's merit, the system still seems to work for many people as I'm sure everyone knows people who have "turned their lives around after turning to the Lord" and such.

The question is the workings of this beneficial system.

A few examples of thoughts to get the ball rolling:

Since the system doesn't seem to be exclusively workable with one god or demon or ancestor etc does this mean we live in a universe filled with all kinds of incorporeal entities just waiting around to lend people a hand with their problems (I find this a rather sentimental notion).

Does it mean that there is, as many seem to think these days, only one such entity (ie God--your god, not their heathen god, of course) who just doesn't actually care as much what you refer to it as as much as devotees seem to think (seeing as the system seems to benefit regardless of mythos)?

Does it mean that such things as belief, prayer, use of psychedelic substances, yogas of various flavors, etc have some direct effect on the world around us (the magical view) or an effect on our minds which tends to help us because our minds are pretty spiffy and well to do themselves (the psychological view)?

Any thoughts?

[TMM]

I don't think Jung was far off the mark with his idea of the God archetype. It explains the prevalence of religious belief throughout history. Despite psychological explanation, though, he didn't consider it an indication against God or spirituality, just an explanation of mechanism. Personally, though, I think that if there were any kind of immaterial existence, it wouldn't have anything to do with such material things as emotions. As such, I don't consider the reality or non-reality of spiritual existence relative to its pragmatic effect. It can certainly be beneficial, assuming beneficial is defined as the spreading of happiness. It can also, like any opinion, be damaging and cause conflict when expressed by people inclined to such things. I never subscribed to the pragmatist definition of 'truth', either, but I'll admit to not really understanding it fully.