I write a lot here about how counterproductive judging others or imposing your values on them is for leadership or influencing them. (Here are five posts on it, for example: Instead of calling something right, wrong, good, or bad, consider the consequences of your actions, What is morality?, On the counterproductivity of motivating people with guilt and blame — aka moralizing, Talking about “truth” or “reality” always confuses things, How willing are you not to judge?)
Thinking about the development of language gave me a new perspective that, I think, helps undermine people’s attachment to calling things right, wrong, good, bad, or evil. This post may sound philosophical or esoteric, but I didn’t write it that way. My goal, as with the posts I linked to above, is to expose flaws in absolute thinking, expose how much you judge and impose your values on others, and to break habits counterproductive to basic leadership skills of empathy, understanding, and influence.
Humans didn’t always have language. Imagine our ancestors fifty thousand or a hundred thousand years ago. They probably mostly grunted like chimpanzees and other apes do today yet they probably had a range of social behaviors like ours.
How can you communicate concepts of right, wrong, good, bad, or evil without language?
I don’t see how you can. I can see how you can communicate liking, not liking, agreement, and disagreement — mainly through your behavior — but not moral ideas. It seems to me that the concept didn’t exist before people could even remotely talk about it.
When people talk about something being right, wrong, good, bad, or evil they imply something more absolute than just their opinion. But how can something be absolute when the concept didn’t even exist at some point?
This perspective reinforces to me that when people communicate morality, no matter how much they think something is right, wrong, good, bad, or evil beyond their opinion, their evaluation is still their opinion based on their values combined with the implication that you should accept their values too.
For that matter, go back even farther to before humans or even apes or mammals existed. Could you describe anything in the universe back then as right, wrong. good, bad, or evil? At some point the universe didn’t even have life. Could you call something lifeless right, wrong, good, bad, or evil?
What do these terms describe if not human behavior? If human behavior changes, as do our values by which we evaluate it, how can they be absolute? You may consider something right or wrong, but if others disagree, what do you achieve by calling them wrong? They call you wrong too. Having many people agree with you doesn’t make something absolute. As Thoreau wrote on slavery, something considered right, good, natural, and just by many:

I know this well, that if one thousand, if one hundred, if ten men whom I could name — if ten honest men only — ay, if one HONEST man, in this State of Massachusetts, ceasing to hold slaves, were actually to withdraw from this copartnership, and be locked up in the county jail therefor, it would be the abolition of slavery in America. For it matters not how small the beginning may seem to be: what is once well done is done forever.

People always bring up killing others as so basic everyone agrees with it. But not only do many disagree with it, many people highly value killing. People highly value soldiers killing and using the death penalty for justice. People value euthanasia. They accept killing in self-defense.
Sometimes people feel adrift when faced with the prospect of letting go of absolutes. I did. But now I find it fascinating and liberating. It gives you resilience from others trying to impose their values on you and exposes their underlying motives. It reduces your arguments. It helps to have the advice for how to communicate without imposing on others in the links above.