It is possible to fight evil and not be angry about that evil
The Talmud (Shabbat 105b) is clear: Anger is idolatry. Anger denies a good G^d supervises everything and is in complete control. Anger can only imply G^d made a mistake and another (so: idol) or I (my ego) could do better.
Anger may seem ‘natural’ but our Sages insist we should and can get rid of it 100%. It may be understandable when a mourner is angry, but generally, anger is an option to shun. If we must have emotions, sadness is OK.
I found that in therapy, anger is an attempt at making it feel safer. Warmly and calmly welcoming the anger then helps. Then the tears or fear come that needed safety first to get out. And crying and trembling always heal.
Living well is the best ‘revenge.’ Let’s honor G^d. Let’s ban our anger. There are other ways than anger to show we care—which we should.
What about when people grossly misbehave, could we help getting angry?
No one and nothing can ‘make us angry.’ Our anger we generate ourselves. Yes, we often employ rationalizations why our anger ‘is justified.’ The most popular excuse is getting angry with someone who’s angry with us.
The offensive evil itself is often worse than us getting angry about it, but that’s still no excuse. Really, no one has our remote control to ‘push our buttons.’ We are in change—also when we feel we are not (yet).
This thinking that only we anger ourselves is not to blame us and make us depressed. Knowing the problem is half the cure. We can stop being angry.
I don’t mean we should hide when we get angry, not act on our angry feelings, or get over them. There might be a place for that too. But no, I mean, we can refuse to make ourselves upset any longer while still caring.
We can say: ‘How terrible for you’ without: ‘They should kill them all.’
We can say: ‘We must stop racism’ without: ‘All racists should die.’
We can say: ‘We need to convict all involved in genocide’ and ensure that happens, without being furious with them. A decent society must condemn evil to help victims and bystanders heal, but not to cool our anger.
We can say: ‘G^d, I strongly disagree and insist it changes’ without fury.
We can say: ‘I see things differently but I understand why you see it like that’ without saying: ‘You are (more) crazy/evil/stupid/wrong (than me).’
We can say: ‘I may make myself angry thinking you easily could act better. But apparently (!), it’s not that easy for you as for me or most people.’
Jews are so loveable. At times, we may be annoying but still wonderful. (Like all people.) We find it impossible to understand that anyone would hate us to the degree they want us all dead. But when we think about what these people learned and how they were hurt and lied to, often for generations, we can understand that it’s not easy on them to respect Jews.
It’s not desperately impossible to respect us; in fact, it’s not that hard. But, nevertheless, apparently, for some it’s not (yet) so simple.
It may also help us to know that the Torah’s hard terms sometimes are not the strong terms of today. Its verb to hate today means: to have some lack of love. Your enemy only means someone you feel annoyed about.
Generally, we do very well already. At funeral, typically, Jews bestow honor on the deceased and talk of our gratefulness having had them in our lives. Often, we don’t say how angry we could be. Jews have no copyright on this.