My opinion is this: if a person realizes that they are doing evil, then they are evil.
And regarding Nowizard's examples: if the Inquisition is not evil, then Satanists are not evil either – they also believe that they are doing the right thing; a man got drunk out of grief and beat his wife – but why did he drink? Alcohol won't make things better, and the problems won't disappear; they will most likely only get worse (it's a pity that not everyone understands this); regarding the embittered person – someone great said: "Revenge is good if two conditions are met: if innocent people do not suffer as a result, and if it does not become the meaning of life."
P.S. And try not to promote any religion anymore.
2) Not everyone knows that drinking only makes things worse; you yourself said that. And some drink to forget, not to remember or see "all of this." Some consider this a way out.
3) That's why he's embittered, and that's why he shouldn't be hated, but helped, because he doesn't understand that by acting this way, he is becoming like those he hates. There is another saying: "An eye for an eye, a tooth for a tooth." If someone hits you once, defend yourself, but no more.
P.S. I won't promise, but I'll try
