Lots of folks in the US don’t really have an understanding of religion as a separate thing from nationality.

They think of “being Christian” as “being like the other white people in my neighborhood growing up”. End of thought.

So drinking beer, watching football, and hating taxes are all “Christian things” to them.

So when they say “Christians — and only Christians — died for this country”, they’re 100% correct, according to their understanding of “being a Christian”. Cuz to them it basically just means “being an American”.

There’s really no way to convince them otherwise. It’s like telling someone that Velcro is really called “hook and loop”.