Christianity is slowly dying. That's good news. The world doesn't need to be run by believers in the supernatural. But part of the reason it is dying is thanks to a subset of Christians. Call them evangelicals, fundamentalists, right-wing conservative zealots, bible thumpers, or anything else you like, they are the reason that young people are leaving the Christian faith in droves.
Evangelicals are mostly YECs, Young-Earth Creationists who believe that the bible is literally true, that the world is only 6,000 years old, that God created two actual people called Adam and Eve who had a conversation with a talking snake and sent the world into sinful chaos. These two people somehow populated the entire earth only to have God destroy everyone a few hundred years later, so that it could then be repopulated by the Noah family after they built a big enough boat out of wood to house at least two of every kind of animal in the world.
One can see how ridiculous this story is and how difficult it would be for a person with critical thinking skills to accept it as literally true. It is obviously allegorical. The scientific method has proven beyond any reasonable doubt that the world is 4.5 billion years old and that life on it evolved. But so strong is their delusion that conservative Christians can't handle the cognitive dissonance that would result from considering the true version of history that they basically isolate their brains from reality, compartmentalizing their bible babble from the part of their brains that get them through a day in the real world.
Fortunately, the younger Christians are beginning to realize that it's all a big hoax perpetuated by their delusional elders. They are leaving the church in search of something else that provides them with equal comfort in life but without all the crazy mumbojumbo. And, it is also unfortunate for the more moderate or liberal Christian churches that do believe in God and in Jesus as God's risen son, but who interpret the bible in a more reasonable manner that doesn't lock them into literalism. Those in the more liberal churches might still harbor their delusions, but they are a more benign breed of delusions. But since the conservative Christians' children associate the term "Christian" with their wack-a-do evangelical group, when they leave the fold they stay far away from other, more moderate, groups who still use the term Christian. Thus all Christian denominations are harmed by the weirdos in the fundamentalist sector. I guess in that respect Christianity is much like today's Republican Party; the nutjobs on the right are harming the brand of the entire GOP party and they don't seem to care, since they are the ones who are right. I guess that's why the tea party Republicans are pretty much all evangelical Christians, too.