Rebbe Hershel of Ziditchov zt'l said, "When two people are pulling at two ends of a rope (tug of war), and one drops the rope, the other will fall." The lesson is that if someone is fighting against you, as long as you fight back, the machlokes continues. But if you let go of the rope, your enemy will fall, and you will be saved. Even better, if you do kindness to your fellow man, the machlokes will end.
Chazal tell us that in the days of Dovid HaMelech, one hundred people died daily. With his ruach hakodesh and depth of understanding, Dovid HaMelech understood that if the nation recited one hundred brachos each day, the epidemic would end, and so it was.
Reb Shimshon Pinkus zt'l explains that the deaths showed that there was a rift, keviyachol, between Hashem and the Jewish nation. There was anger from Above, which resulted in these deaths. When there is a rift between people, and one of them smiles and speaks kindly to the other person, the machlokes won't last for long. You can't be angry with someone so kind to you. Dovid HaMelech understood that if Klal Yisrael came to Hashem with one hundred daily praises, the rift and the wrath would end, and goodness would come to the Jewish nation.
This is certainly an excellent counsel to act towards your fellow man. Be kind to them, even when they are cruel towards you, and goodness will come your way. If you try to harm them, it (a) is nekamah, (b) won't work, and (c) It will just fan the flames of the machlokes.
