The America I grew up in was a Christian America–but its movies, TV, and books were already heavily non-Christian. Looking back on it, I wonder why that was. It surely has a lot to do with the way America is now.
I don’t remember any such thing, back then, as “Christian fiction.”
Maybe if we hadn’t cut the Christian religious dimension out of our fictional worlds back then, we wouldn’t need a special category for “Christian fiction” now. I am sure no one noticed it back then–although if anyone did, and had the courage to speak up about it, it doesn’t seem like anyone was listening.