What strikes me is how unlikely a scenario it seems. There seems far more danger in secular fundamentalists seizing control and creating a dystopia where Christianity is outlawed.
Also, what seems troubling to me is the possibility that such a work will only further stir up animosity towards Christians in our culture. People may read or watch this and make negative generalizations about all Christians. It reinforces the negative stereotype that Christians are hypocritical, uncaring, and simply want to control everyone else’s behavior. Even though I’m sure a discerning person could view this and make the distinction between fictionalized fundamentalist Christians and the vast majority of actual real-world Christians, I think many people won’t make that distinction.
But I haven’t read the book nor seen the movie. I’ve only heard about the general premise. So I don’t know how much these concerns are warranted. That’s just my best guess from what I’ve heard about the storyline.