One thing a knowledge of evolution does is not require belief in a creator god who is either terrifying or demanding worship as a price of continuing to exist. Evolution neither demands a belief in a god, nor does it prove there is not one. The fact that this could all have happened with no creator does not mean there is no creator. As a corollary to that-- all religions being wrong does not prove there is no god.
In comments earlier, someone mentioned that rather than us being created in God's image, we created God in ours. That pretty well says it all and we see it in diverse cultures how they interpret what they think God must be and those interpretations differ with their life experiences. As another commenter mentioned the concepts of what God must be change with time.
Man has seemingly always sought answers for why we are here, and sought to control the environment which at the first mostly was through rituals although there were other environmental tricks, like forest fires or gravity to secure food and increase productivity. Sometimes what was done had no concern at all for the long term... mostly it had no concern for the long term.
From the time mankind had the ability to communicate with each other, there were signs he also wanted to communicate with a possible deity. Most cultures have a belief in some kind of deity with suggestions or demands on how to please that supernatural power. If there was a bigger guy out there, man was going to try and make peace with him/her/it.
The same traits are in modern man albeit with more possibilities for how. Some seek answers through religions and some through scientific explorations. [Science] as a tool has been with man a long while.
Man has always had a mix of reasons for using science. Some was to explore the mysteries of life but other reasons included improving technology to make physical life better. I think there has always been though some pure science without the need to make a profit from the information. What is this all about? What can we learn about it? Those kinds of questions aren't necessarily leading to a profit materially anyway. Too often, it seems today, the goal is exploitation. If we can't use it, why bother doing it? Universities, where much research has always been done, depend often on corporations for donations and corporations want them researching what they can utilize.
Back to why evolution matters. What are the lessons from evolution?
When I began researching evolution, the first thing that seemed to be important is, contrary to how some talk about it, the theory of evolution didn't begin with Darwin nor did it end with him. He simply laid out, through observation, evidence for the process by using animals living today that had been isolated from each other noting their differences. He used those observations to propose that this was also how human life evolved, and of course, lit an explosion from the religious.
Darwin began with a belief in natural selection as the primary reason for what we might see today in species. He came to see it was possibly more about sexual selection (wrote a book on that too) but he's forever stuck with being identified by natural selection and survival of the fittest. Instead it's quite possible that a lot of our changes came about through the same thing that happens today-- Marilyn Monroe types for one generation and Angelina Jolie for another-- figuratively speaking, of course.
To come up with his theories, Darwin couldn't do the DNA testing we can today and the missing links for mankind weren't yet found. Frankly finding bones from a million years ago isn't all that easy and fossils can often be equally destroyed even for bigger animals than 'protohumans.' Remember the earliest development of Homo sapiens came from Africa and by the time it spread out into the rest of the world, some of the initial changes had already occurred.
Proof positive has not stopped man from wondering. Early Greek philosophers posited questions of mankind having evolved. It wasn't even really controversial until religious revivals made it heresy to even question the account of creation in Genesis. It was not okay to say we weren't the center of the Universe (which some still want to believe even if they have given up on the sun revolving around the earth).
For a period of time scientists who dared explore any alternative were threatened with death or at least exile. During that period to talk about what I am here could have meant torture and death (still could in some cultures today). It was a threat to their religion and religion is about power. Some of this was because if the earth wasn't at the center of the Universe, was man the center of a god's interest? Were we really the most important things here? Heresy to suggest otherwise. If God isn't constantly tweaking things, how do we explain what happens?
Science and religion seemed to often be on a collision course. Some see it that way still today which is why science and the intelligentsia are condemned so heartily by a certain group-- knowledge threatens a certain type of faith.
Darwinism is not the same as evolution nor does evolution depend on his theories and observations. There is way more evidence by now to show missing links, to better understand the anthropological record and DNA to let us see the path even more clearly that life has taken to get to where we are, which is not where we will stay.
This whole subject of evolution naturally leads to spiritual questions which is why it so upset religious types.
Evolution's study does matter but I think it's more where it leads than simply whether we and apes descended from a common ancestor. The bigger question is are we free to think or not? Do we dare explore evidence or is that eating from the forbidden apple? If we believe in a dictatorial god who is threatened by our thinking, than free-thinking is a danger. Exploration of new ideas is heresy and puts at risk the whole culture because who knows where this god might decide to show displeasure.
Denying evolution denies science and impacts our whole culture and its advances. To be honest, I wouldn't vote for a president who said he didn't believe in evolution. What else would that mean about what that person? Where would that mean they put science? Were they free to think or had they already figured out everything and were going to defend those answers no matter what proofs came along? Can they assimilate new ideas? I'd assume not.
Evolution is about a process not a religion. There are no rituals, no special words one must say. Belief in it doesn't deny or prove the existence of a deity.It does though posit a very exciting possibility-- that god is a scientist, a being who is fascinated by life itself. It also indicates a planet that is very old and would require a very patient god to set this in motion and then, if he pays any attention to it, sit back and let it play itself out-- the things that worked so well or didn't. (Yes, I know, we are the ones who define time by earth standards and this all is assuming one believes in a god which an evolutionist might not).
What if instead of looking for control, we accept the earth is in flux and we are along for the ride doing the best we can with it? What if we try to work with it rather than against it? To me, those are the lessons, among many others, of evolution.
Studying evolution, learning about it, matters because it means we aren't afraid to explore truth. We don't have to force that truth to go places it doesn't naturally go.
Truth is my idea of how we cooperate in making this earth and our own lives all that they can be. To fear reasoning is to put god in a position that religion might have put him but I don't see any proof of it in nature. It does no justice to the possible creative genius behind this Universe and many others.
Oh, and I am most definitely not done... :)