It always seems like there is an implication to 'evil' that bad or negative or undesirable don't have. I challenge you to actually define what you mean, by evil. This answer gathers together some candidate definitions: Does philosophy have a dark side? I can't help but think the word is a hangover from Christian thinking, where practical moral and spiritual badness have some kind of Venn-diagram convergence labelled 'evil'. In particular it seems to mean bad from which no good can come, irredeemable bad, beyond salvation...
For contrast, this answer compares the Buddhist paradigm, in which there is no irredeemable, only actions going further into ignorance and delusion about your own and others true interests: Was Nietzsche more compassionate than the Buddha's teaching?
A lot of our moral reasoning comea from intuitions, and there is good reason to think at least the most cross-culturally shared have a basis in evolution. See Moral Foundations theory, the Social Suite, and how our almost unique intuition that we should have sex in private enables greater cooperation, discussed here: What binds us to our moral duties? In this picture the strongest moral lines we draw, are the lessons that have run deepest. But, for every rule against murder, there has always been war and the need for some to kill on purpose and be celebrated for it. Many will claim rape has just always been a crime everywhere, but marital rape was only made a crime in 1992 in the UK, and in all US states only a little earlier. When we go a little further back making slaves fight to the death in the Colliseum in Rome was seen as literally the height of civilisation. There's also a stubbornly persistent percentage of psychopaths born everywhere around the world, who do not feel the same intuitions. So it's difficult to go to physical or cultural evolution for guidance on what is acceptable and what beyond the pale. Hume's Is-Ought argument puts the tin hat on the failure of that avenue. Our morality, moral reasining and moral intuitions, seem to be emergent from how we structure our society, as discussed here: Is artificially generating images of minors in sexual positions unethical?
You can look to moral condemnation of climate crisis, but I don't know if you've noticed, that doesn't seem to work very well. Look at the weird hostility to Greta Thunburg by some people, for instance. I'd suggest there's a bigger cause of problems, and solutions, that we don't like to look at because it involves essentially everyone. Where is your pension invested? If you haven't consciously decided, then it will be being invested in new fossil fuel projects, because those oil companies are in the top 100 or 500, and ordinarily pensions just split their money like that. Now, are fossil fuel companies a good investment for over the next two decades? While ending supply of Russian oil and gas has temporarily masked this, I suggest they are almost certainly not good investments, and it will be ordinary people and their pensions that foot the bill, of dwindling supply, clean-up costs, and the gigantic progress in wind and solar and storage that will make them increasingly bit-players.
The sociologist Durkheim grappled with the full range of human religious behaviour, beyond the Abrahamic sphere. And he identified what we hold sacred together, as being what binds the group that does so together. That might be an altar, or the social contract (violation leading to revolution), or scientific method and norms for the international scientific community. Rather than think our strongest moral intuitions and norms have been around longest, which they probably haven't, I'd look to which groups our bound most strongly and effectively together. Habeus corpus and seperation of powers that makes for an independent judiciary, has enormous practical consequences for cooperation and solidarity, and mitigating risks of tyranny. The rules-based international order with commitments to end war crimes, uphold human rights, and trade rules, has created a political trade and economic block that can, fingers crossed, cooperate a lot better than say Russia and China.
Where we draw our lines is important, and I think it's easy to observe peer-pressure shapes behaviour more than laws. But feeling condemned morally, by a given sub-group, is just one incentive among many. I suggest informed public policy should not be focused on defining good and evil, but on incentives and motivations - albeit powerful internal ones like wanting to be a good person. Good and evil are powerful for narratives, for drama. But worryingly often we find the people who turned out to be evil, told us what we wanted to hear, and we didn't feel the good were good because they told us we were being bad, and our miral intuitions saud, that can't be right..
I feel like your post implicitly relates to Nietzsche, and his book Beyond Good & Evil. For duscussion of what he meant by that and where that would take us, see this answer: Nietzsche on balancing service to the creation of (or becoming) the Overman and living a life of ones own choosing?
