Religion is by nature man-made.
Jung might argue that point. He defines religion as a collection of archetypes, and archetypes occur naturally in our brains. (More on that in a moment.) Therefore it could be argued that religion is natural, and not man-made.
. . . .for example believing in creationism when evolution is a scientifically established fact.
There are no facts in science, only theories which have been proven "true beyond a reasonable doubt," to borrow the language of the law since the language of science is not well suited for communicating with laymen. We cannot say with 100% certainty that the theory of evolution will not one day be falsified, but the
probability of that happening is so slight that it is
unreasonable to dwell on it. But to get back to your statement, the reason many religious people feel compelled to doubt the theory of evolution is that they have not been taught to distinguish between
evolution, which is the slow changing of one species into another through genetic processes, and
abiogenesis, which is the transformation of non-living matter into living matter. Evolution is a
canonical scientific theory supported by a plethora of evidence of several different types. Abiogenesis is a
hypothesis to explain how the very first living things arose. There is no observational evidence for it and reasoned evidence is weak since we don't understand how major parts of it might work. The best evidence for abiogenesis as the source of life is the syllogism:
- The universe was at one time a point mass of infinite temperature.
- Life could not have existed under those conditions.
- Life exists now.
- Therefore, at least once, life arose from non-life.
This is a rational argument and therefore is automatically elevated above the scatterbrained attempts at "reasoning" offered by theists, along the lines of "Hey dude, there are freakin' butterflies! That beauty is proof that my god created the universe." Since it's the only hypothesis about the origin of life that is even vaguely scientific, we all cluster around it for lack of anywhere else to go. But it is so full of gaps that it's impossible to test, much less prove. It has not been proven true beyond a reasonable doubt, so it is only a hypothesis.
Come back in a hundred years when we've figured out how to turn inorganic matter into organic matter using chemical reactions that could reasonably have existed on the primordial earth, and then we'll talk about "proof."
In the meantime, many religious people back themselves into a corner by feeling compelled to deny evolution, because they don't realize it does not conflict with divine creation. No less august a religious authority than the Pope accepts the theory of evolution without shaking his faith in abiogenesis, and Catholic educational institutions teach evolution unremarkably. The same is true of most mainline Christian denominations, as well as other Abrahamist and non-Abrahamist communities. The evolution denial movement in America comes from the same Bible Belt as the fundamentalist biblical literalism about the "young earth," created in 4000BCE with all species already in existence.
There is no empirical evidence for the existence of God, at least not to my limited knowledge.
The only "evidence" for god(s) is an
archetype, a pre-programmed instinctive belief hard-wired into our brains by an accident of evolution. (A one-time survival trait, or the result of a genetic bottleneck, etc.) Unfortunately a belief that a person is born with is older than all other beliefs acquired through learning and reasoning, so it "feels" more true than any of them. To many people it "feels" so true as to be accepted as intuitive and uncontroversial. Anyone who does not experience this instinctive belief, or has lost it or shed it, is regarded as mentally unbalanced, perverted, stupid, etc., just as if he lacked the also-instinctive but scientifically corroborated belief that he must eat in order to live.
Indeed the universe appears to be a chance occurance, in this reality things seem to have fallen together in ways that ultimately allowed us to emerge without outside planning or influence. This does not in any way exclude the possibility of a creator, it may have created the universe to look that way.
This line of reasoning violates the definition of "the universe" as
everything that exists. The creator by definition is part of the universe. Saying that he created all the parts we can observe does not answer the recursive question: How did he come into existence?
People who say "God created the universe" and then imperiously assume that they don't have to answer the obvious follow-up question "Okay then, who created the god please?" are being disingenuous. This is not scholarship so we are not obliged to treat it with respect, and we are quite justified in keeping it out of our educational systems.