Parshat Pinchas addresses the question as to when is an individual allowed to take the law into his hands. Pinchas was one such person who acted on his own in a zealous fashion for the sake of Hashem’s honor.
His actions in killing זמרי and כזבי, were at first frowned upon by the rest of the Jewish people. It was only after Hashem clarified that he acted correctly, was he reinstated as a hero.
Pinchas was referred to as a קנאי, a zealot. In order to be considered a zealot and not a mad man, one must be certain that he is acting solely for the sake of Heaven. He must be a virtuous person in order to justify such zealousness.
The Gemara in ערכים says that today, no one is capable of giving rebuke. It is so difficult not to come across as self-righteous and judgmental. Pinchas acted with the goal of acquiring peace. He was blessed with the כהונה as his reward for his efforts.
Anyone who thinks he’s on the level of Pinchas, is arrogant and mistaken. We should only strive to be like him, and act strictly לשם שמים. This, too can bring Hashem’s honor and glory to the world.