A brief discourse on religion:

Core premise: Religion rests on a foundation of basic primate psychology, as harnessed and directed by a “ruling class” and modified by a genetic based peculiarity of modern physiological differences throughout the population.

We are all born into the world naked, wet, and hungry.
If not for a benevolent external force, to protect, feed and teach us, we would likely die.

Initially this need is filled by our parents or caretakers.

As we become more self aware, it becomes apparent that our parents are -almost- as baffled as we are about how things work. The onset of puberty hits about the time this self awareness begins, which further confuses things. (Hormone induced irrationality - in many species young members forever part from their parents at this point)

In humans the desire for a benevolent external force continues, even though it ceases to serve a beneficial purpose, since our parents lose their omnipotent status, and progressively become more “peers” than “superiors” as we age.

The “God” concept satisfies what is basically an infant primate's emotional need, brought about by their initial helplessness, extended infancy, and lengthy development.

(For a detailed discourse on the history of religion, see elsewhere)

This basic need was harnessed by those who wished to control: first the medicine man, then the priest, then perhaps the Pharaoh, all of whom are subject to the same unfulfilled need, so it is a self perpetuating and attractive proposition...

In parallel to this, a secular government also began to arise, to handle the more practical matters of "earthly" life, like war, or irrigation, or civil engineering while the religious class invented endless detail about the popular gods of the period. In so called "primitive" societies enormous pantheons of gods to handle every imaginable event or circumstance in life (the modern equivalent to legislation, that attempts the same thing: namely to address each individual circumstance individually, instead of the more criteria based approach of science or engineering) so the older a religion, typically the more complex it is, since at its inception it had to encompass a societies entire world view to stay consistent with the observational powers of a societies members. Later religions are simpler since a world view was already well established and mature, so it only had to address the “Spiritual” aspects of a worldview.

As secular government manages the basic needs of a society (whether this management is needed, or simply benefits the managers) it inherently gathers collective power to itself, where religious government provides administration of law (tribal rules) that are initially attributed to a god and in modern societies have spun off into elements of secular management (Federal and state law) religious government over time cedes authority to secular management since gods (and their self appointed conduits) make minimal contribution to the practical business of hoeing the fields, regulating commerce etc.

And eventually religion takes its place as it’s reflected in the modern (western) world, something that influences politics and popular opinion and proclaims itself an authority on morality.

And this would be the end of the matter (a nearly steady state of asymptotic decline in religious influence) if not for two compounding factors: Tradition. And a peculiar variation in brain architecture – you may (or may not) remember a Time article called “god vs. Science” and the whole groundswell of additional articles and books preceding and following it showing that roughly 50% of individuals are neurologically capable of having “religious” experiences and that, conversely, the other half don’t. This insures that religious conflict will likely be with us indefinitely unless a conscious effort is made by one half to convert the other half.

(Ok you caught me! This paragraph is firmly tongue-in-cheek)
Since the basis is genetic, it’s likely that retroactive birth control is the only method likely to yield measurable results. Given the moral complexity of that approach, it is unlikely to be enacted unless some dramatically polarizing event influences popular perception about the significance of the rift. And the desirability thereof…

So the genetic predilection: is it a beneficial survival mechanism? Gives us the ability to form social groups (Tribalism? A leader-follower instinct, something else?) or is it some mammal holdover, an accident, or may be a brain defect, built right into half of us?

That combined with this inherent longing for SOMETHING to care for us in a generally indifferent universe has one guaranteed effect: it makes at least 50% of our population nearly incapable of resisting the premise that some external force exists, and that it is interested in their lives.

This firmly places the tools of manipulation in the hands of those perceptive enough to recognize it, and ruthless enough to indoctrinate rather than educate.