science and the post-Christian trinity
It is no accident that anti-Christians believe in a mythological civilization-spanning, almost Manichean struggle between science and Christianity (where Science takes the part of the light and Christianity the part of the darkness). The reason that they believe in this myth is that they see science as a tool for destroying Christianity, and so naturally they think that Christianity must have fought against science to avoid being destroyed.
History shows little support for any sort of general Christian antipathy to science--as opposed to focused opposition to particular scientific theories--but science certainly was used as a tool, or rather a pretext for attacking Christianity.
The original attack on Christianity came in the form of an argument something like this: we no longer need revelation because we have a philosophy and a methodology that will tell use everything we need to know. The problem with this primitive scientism was that there are things we need to know that science cannot tell us: Why are we here? Where are we going? What is wrong with us? How shall we then live?
These are the Big Questions that religion answers. The answer to the last question is easy because that was the whole point of the anti-Christian movement. The answer they are looking for is: live however you want to. But to get this answer, the anti-Christians needed answers to the first three questions to support their preferred answer to the last one. This is where the post-Christian trinity of Darwin, Marx and Freud come in.
Darwin's theory of evolution tells us why we are here. It says that we are just accidents resulting from billions of years of chance events directed by whatever arbitrary conditions happened to exist at the time. In other words: why are we here? No reason. Just that our ancestors were the best survivors.
Marx's theory of history tells us where we are going. It says that human society is inevitably directed towards a future Utopia. We as individuals will cease to be; all of mankind will eventually be subsumed into society like drones in a bee hive with all thoughts directed to nothing but the betterment of society. In other words: where are we going? Nowhere. Our descendants will just be cogs in a machine.
Freud's theory of the subconscious tells us what is wrong with us. It tells us that hate, greed, fear, and self-destructive compulsions are caused by our subconscious--the scientific version of demon possession. The subconscious is trained by childhood events like potty training and little girls seeing their baby brother's penis when mother changes the diapers. When we do evil, it is not us that does it; it is our subconscious. In other words: what is wrong with us? Nothing. Just that we have this subconscious that we need to retrain.
These theories are the foundational doctrines of the of post-Christian religion in the West. They have all been used as justifications for doing great evil. In addition to the horrors committed by the Marxist Communists during the 20th century, the horrors committed by the Nazis were inspired by Darwinism. Thanks to Freud and other theories descended from him, millions of children have been raised without discipline or a sense of responsibility, others have been drugged into torpor to repress childish energy, and still others--we don't know how many but we know of some--were sexually molested by their own parents to keep them from growing up "sexually stunted". Freud-inspired theories have also let to the release of dangerous, violent prisoners to continue raping and murdering their neighbors, and to the mentally ill being tortured as a "cure".
It is frustrating that even though these theories were all specifically created to oppose Christianity and have such anti-Christian implications and have such horrific histories, that so many Christians still believe them. Too many Christians accept "science" as a pseudo-religious authority capable of enlightening us on things that science is wholly incapable of addressing. Science can tell you how the material world works. It can tell you: if you have this cause, then you will have this effect. It can tell you: if you want to get this effect, you can do it with this cause. But the methods of science are powerless against the Big Questions, and any scientific theory that claims to address one of the Big Questions should be taken with extreme skepticism.