In the beginning of Parshat Korach, Rashi writes that Pinchas's lineage is referenced to counter claims that his zealotry was due to a defect from his maternal grandfather, Yitro. Instead, his lineage proves righteousness and purity of intention. The Rebbe explains this demonstrates how one's actions in defending the truth can create peace.
The Midrash tells us that the tribes disparaged Pinchas for killing Zimri, saying he descended from one who fattened calves for idolatry. Thus, his lineage was emphasized to validate his actions. The Rebbe explores this further to understand how zealotry in divine service should ideally manifest.
Pinchas’s reward of a 'covenant of peace' suggests that his act wasn’t merely destructive against evil but ultimately constructive, establishing peace among Israel. The Rebbe elaborates on how true zealotry results in positive outcomes when it stems from pure motives aligned with divine will.
Furthermore, the Rebbe teaches that individuals who act decisively for sanctity hold an irreplaceable position in spiritual leadership. Their actions prompt divine favor, leading to universal benefits like increased faith, morality, and harmony.