One of the problems with the historical Christian system, particularly in the US, is that its predicated on people living in the same place and going to the same church intergenerationally. As people are forced to migrate in order to find employment, they become untethered from their heritage church sites and the attendant communities that added real value to church membership.
The hyper-capitalization of the modern American Protestant movement hasn't helped, either. Very hard for the Southern Baptists to maintain participation when GenX, Millennial, and Zoomer cohorts no longer want to live in these heavily religious communities. They move to areas that don't have these highly active and Christian-dense neighborhoods. They fall out of the hyper-religious social circles. And they lose touch with the media and culture that ultimately drive these religious groups insane.
Meanwhile, the low housing prices and the increasingly finance and tech focused economic sectors are bringing in large numbers of religiously rivalrous migrant populations. The most common new religious constructions in the US are Mosques thanks to a large influx of Arab, Persian, and East African migrants. And because migrant populations and religious builders love cheap land, they're often showing up in and around declining Christian communities.
If you're out living in LA or Tampa or Houston and you're wondering why folks in Peoria, Indiana or Chattanooga, Tennessee or Tulsa, Oklahoma are losing their fucking minds over the super-scary illegal immigrant / Radical Islamic invasion, this is a big reason why. Their kids are all leaving for the coasts while lots of unseasonably tan people are showing up to take their place.
That... actually makes a lot of sense. Couldn't figure out why America, the land of immigrants, was so hostile to new people but now I can see why a poor old conservative feeling abandoned and surrounded by confusing things might think Trump actually makes sense.