"Revenge is mine," thus says the Lord. He demands the ultimate in loving when He gave the command: "Love your enemies, pray for your persecutors." M. Scott Peck, famous author, says: "Forgive is an interesting word. It does imply a giving  a giving in or giving up . . . . A person is caught between the need to give up something and their will to hold on to it or their anger at having to give it up." (A World Waiting to be Born, p. 122) I guess in every conflict, one of the factions may be right and one of them is doggedly attached to the notion that he/she is right. But when we do look daggers at an ‘enemy’ usually it is because that enemy has crossed ‘my’ path. We want to stick to that notion that we are right and the ‘enemy’ is wrong; the enemy has caused us injury and we are hurting inside. When we find ourselves in that position, it is time to introduce into our thinking the mystery of divine mercy, supremely revealed by Christ.
The mystery of divine mercy is the source of a life different from the life which we build with our sense of righteousness and our facility to draw perimeters around that often-illusory notion. It is in the name of this divine mystery that Christ teaches us to forgive always. When we pray, "Our Father . . . forgive us our trespasses as we forgive those who trespass against us", we say a truth about ourselves and a truth about others. The very truth that we trespass over one another when avowed is an act of humble acceptance of the frailty of our humanity wounded by sin. This acceptance goes hand in hand with the call of fraternal solidarity which St. Paul expressed in his concise exhortation to "forbear one another in love" (Eph 4:2). What a regard for man is found here.
It doesn’t mean at all that to forgive is to be indulgent towards evil, towards scandals, towards injury or insult. In any case, reparation for injury, and satisfaction for insult are conditions for forgiveness. Love is all necessary here. He who forgives and he who is forgiven encounter one another at an essential point, the dignity or essential value of the person. (John Paul II, The Mercy of God, 14.) The Church considers it her duty and the purpose of her mission to guard the authenticity of forgiveness. Thus the Word says: "This will prove that you are sons of your heavenly Father, for His sun rises on the bad and the good, He rains on the just and the unjust . . . in a word, you must be made perfect as your heavenly Father is perfect." Indeed, powerful is love when it forgives.