How many people are familiar with Plato's Republic? In this treatise there is a story known as "the Cave".
According to the story line if I remember correctly, a group of people were kidnapped at a very yooung age, by a second group.
They were bindfolded and taken to a cave. They were set on the cave floor facing the back wall of the cave. The cave is deep enough that very little light penetrates. They were tied up, such that they could not move or look behind themselves. They never see their captors face on.
On various occasions their captors would build a bonfire behind their captives. Their captives would dance in front of the fire, but behind their captives. Their captives never actually see the captors, But instead, see their captors shadows projected on the back of the cave wall in front of the only direction the captives could look. The captors spend their entire life under these circumstances.
As far as the captives could tell their captors were 10 feet tall as shadows project larger than the source at a distance. They saw unusual projections emanating out their captors heads in the shadow orojections. For all the captives knew, this was the true appearance of their captives. This is the only paradigm they knew.
There is more to the story that Plato was addressing. But for my purposes. Religion (any) is like the Cave story.
Religion captures people at an early age. They blindfold them with dogma. The captives to the religion are kept in the dark from any opposing ideas or paradigms. The ceremonies are made to project larger than life shadows (cathedrals, giant crosses, etc.). The religious captors dance behind their helpless captives with opulent ceremony and pomp and circumstance. Their captors holds their captors at arms length and never really show themselves for whom they really are. They are told that what they see and the dogma they hear is reality. The captors do not stand a chance.
Plato's cave is simply a warning that unless you are able to freely access all information you can be fooled from birth into believing what you are allowed to perceive is the normal and is all there is.
It is a allegory these days better summed up in the adage that the best form of maintaining government control is the so called Mushroom method ...keep them in the dark and feed them bullshit.
Modern electronic communications and wide spread dissemination of knowledge has largely put an end to this, except for those poor souls so accustomed to their shackles and the darkness of cave that they prefer not to turn around and look outside. The blissfully and willfully ignorant.
Our perception of reality is just an illusion, and I think the illusion is less real than a shadow world—it is a total fabrication created in our thoughts. Underlying reality is of a different order of existence and can not be understood in terms of the space/time/objects model. There is no location, no objects, no causation, no motion except in our minds.
Those people in the cave are captives of limited perception. A few people throughout history have had glimmers of ultimate reality beyond, and their insights have sparked religion, science, art and philosophy.
Read The Republic in college.
Haven't heard the interpretation that religion is the cave. It can fit in our modern times.
For me, I always thought The Matrix was a good modern day Cave allegory where humanity is born into a world of false images and perceptions with no idea of true reality.