The world revolves on an even axis of mercy and judgment. These are the two legs that support the world. When someone has reached the level of feeling G-d, he can easily see these attributes and know how Hashem is relating to him, either in mercy (Chesed) – when he receives the gifts of bounty of health and happiness (the Good Side) or when he is given a test, G-d forbid and he has to overcome the hurdle of judgment -Din (also known as the Other Side).
When we pray to Hashem, it is usually done through supplication, an expression of mercy. We also do mitzvoth, good deeds, in happiness always because chesed “makes the world go around” and we are actually copying Hashem, who showers down bounty upon His creations. Din is what gives the unending bounty pouring down its shape. It contracts and actually puts up walls to contain the good in this world. Peace is a time of chesed. War is a time of Din.
Our holy Rabbis told us long ago that the mighty warrior who will fight the final war prays in the aspect of Din and actually descends into the throat of the Sitra Achra (The Other Side). He does this in order to redeem lost souls and ultimately destroy the entire realm of evil. This type of prayer causes the Other Side to vomit up all of the damaged souls and prayers it has swallowed, until at last, evil vomits up its very life force. This comes up in the form of converts and righteous gentiles who join the Jewish people in their day of war and redemption. G-d’s radiance and glory will then become revealed, shining so great a light even in the darkest of dark unholy places. The final phase of this process is when total truth is revealed by the Mashiach and the entire world is at peace.
Peace is the harmony achieved from the direct recognition of the logic of good and evil and the coping with these challenges. This is not achieved by hiding from them, pushing them away or building a “CHOP” area but by processing and refining till they become dust. The Cohen prepares the dust of the Red Heifer fixing the impurity of death and Tum’ah to life and Tahara but he has to get his hands dirty as he does it. This is the only way he can fix it. We were not put into this world to stand by but to stand up. We were commanded to fix it.