Or Judaism, or, I expect, Islam. And not just in the US, but anywhere. The foundational texts are just a feedstock for the expositors -- and practitioners. Which brings me to my next point:
> As is frequently lamented, the U.S. is a nation of Bible owners; not
> Bible readers. As such, I don't think it's the actual substance of
> the faith that explains why people are attracted to it.
There's a mistake here -- an understandable one, of course -- to the effect that the foundational texts represent the 'substance of the faith.' But that's backwards. The substance of faith is praxis -- social praxis at that. It's an intellectual's deformation-professionnelle to overestimate text and dogma.
The supposedly foundational texts are to religion what coal mines are to industrial society -- a source of raw material. Rich, high-energy raw material, to be sure. Some great stories and songs in those books, and even some interesting notions. But everywhere and always, they're re-shaped and re-understood to fit the actual felt needs of das Gehirn der Lebenden -- to borrow a phrase from the Old Man.