Actually, if you want references to religion in The Wheel of Time, look at the Darkfriends. And the human equivalent to the Myrdraal, the Whitecloaks. When the Whitecloaks catch some actual Darkfriends in their Citadel of Light, the Darkfriends are reciting a credo and a catechism. And they talk about The Great Day of Return - now what is one of the most "popular" religions in the US at this current moment, with televangelists understandably drawing the mockery of others - remember that 80s movie Pass the Ammo, starring Tim Curry as the hypocritical televangelist whose hand is always out for the poor folk's money?
My guess is that RJ saw what was going on when he was demobilized/discharged, with books like The Late Great Planet Earth in circulation, and televangelists raking in the dough while wallowing in their depravity, and it ate at him until he turned it into a story, just to get it out of him, so he could stop thinking about it.