In Mathew 5:9 Jesus says "Blessed are the peacemakers, for they shall be called children of God." We are sent into an ugly, sinful world filled with violence and hate, to be peacemakers. He doesn't give us a choice of whether or not we want to do this, nor are we given the choice of the kind of world we live in. So, as bad as things may get, this is the only world we have right now, and if we are to be true to our Lord, we must be peacemakers.
Peacemaking is different than peacekeeping in that you don't need guns or weapons to be a peacemaker. Being a peacemaker isn't necessarily about actions you may do, but about an attitude you may have towards others. It's not about coming into a situation and forcing cooperation, assuming that will bring peace. Jesus is not talking about inner peace, like feeling good about situations. He is talking about the reconciliation at all levels of human engagement, at all levels of our relationships. The Hebrew word for peace is shalom (שלום), meaning one who has, or has been provided, what is needed to be whole or complete. http://www.ancient-hebrew.org/27_peace.html. This is the kind of peace Jesus is talking about.
We live in a very divided world, but Jesus did not delight in division, bitterness,
or a divide and conquer world. He delighted in making peace whenever and wherever possible. To truly make peace takes a very special person, one who recognizes they are poor in spirit, one who mourns along with God about the sinful broken world, one that hungers for righteousness, and one who has, through God, been made pure of heart. It takes a very special breed to be peacemakers.
The God we serve is the God of peace. Through His Son, He has brought peace. It is our job to repeat what He has done. The world sees peacemakers as the ones who go to war and fight for the rights of their own people, they take sides and through violence try to come out on top. but, Jesus says wait a minute, I am not that kind of King. I am a peacemaker, I am not here to take sides, I am here for all people, I am the Prince of Peace. So, if we really want to be called children of God, then we need to truly be peacemakers.
The whole idea of making peace comes from actively seeking to do it. Not just looking for conflict and trying to fix it, but always staying aware and always being the hand and feet of Christ, to actively bring peace and perspective to all situations for ALL people. Picking sides is for those who refuse to see themselves in need of God. Peacemakers are those that make peace through their own humility and need for the other.