It's hard to imagine how opinions or actions which we currently view as evil are considered good by others. It's hard, but not impossible. A few years ago I had a different worldview than I have now. I didn't really understand what epistemology is, and I wasn't actively working to improve my own justified beliefs. My perspectives on morality were, in many ways, unexamined. I considered some things "wrong" and other things "right" without justifiable reasons, other than it's what I had always known.
Some of the people doing "evil" things today are in a similar situation. They simply don't know any better and what they are doing is seen as "good" by them and their community.
More important still, some of what you condemn as "evil" might justifiably be good, and you are unable to see that truth for what it is because of your own tribal, in-group perspectives.
I'm not arguing for moral relativism. I'm arguing for fact-based, evidence-loving, open-mindedness which values wellbeing. As adults, we shouldn't fall back on childish "good guys versus bad guys" cartoon thinking. The world is much more nuanced and context matters. At the same time, we shouldn't remain silent about the harm we see happening in the world. We should talk about it and share our opinions on why it's happening. We should engage research and have open, honest discussions. We should be willing to be wrong. Possibly even so wrong that the "solutions" we propose could be part of the problem. We have to engage without fear.
As soon as you state your opinion, others may oppose it. That's okay. That's when everyone involved can grow. Divided, we condemn. Choose love and understanding over fear and hate. Together we can be unique, respectful, and free.