Rav Chatzkel says (Ohr Yechezkel: Middos - Laasos Nekama BaGoyim) that we are all born with an ingrained trait of hatred. Unless we rid ourselves of it, it will haunt us from time to time in our lives even if we think we are above it. Often we may think that we are preaching a good cause but it is a mere cover for our instinctive trait of hatred coming in disguise.
Take the capture of Eichmann, said Rav Chatzkel right after he was caught and brought to Israel. That is all people and the newspapers are talking about all day. The public brags that we merited to take revenge in a murderer and Hashem is the master of revenge. The truth is, says Rav Chatzkel, this idea is nonsense and far from any understanding of Torah.
If we found murder so terrible why are we not shaken by a recent earthquake that took the lives of thousands, asked Rav Chatzkel? Do we think taking revenge on Eichmann is going to bring back six million lost lives? Why is everybody so busy with him, is he the only murderer in the world? What is the relevance of the number of his murders, if it is only a product of his ingenuity and opportunity? Eisav's lifeblood is the sword and anyone is capable of doing what he did.
Our excitement of his capture stems from our desire to be victorious. It has nothing to do with avenging Hashem's name. All talk of that is idle chatter. The lesson we need to draw from Eichmann is that if we do not root out hatred from our heart we can literally become an animal in every sense of the word. And this is only through Torah.
We must see that our outlook is far from the Torah. Al Pi Torah we must not look at the worst Rasha with complete hatred even for committing the most heinous crimes. We should only be concerned with Kavod Shamayim which demands that a Rodef be put to death. But to seek the blood of a murderer is forbidden and we must not be happy with his day of reckoning. We must not forget the concept of Tzelem Elokim.
While these words seem far from us, Rav Chatzkel says that these are the foundations of mussar and someone who is far from mussar can not comprehend this at all. Scary...