One of the greatest lessons our Lord Jesus Christ taught us is the lesson on forgiveness and love. Jesus Christ said that the new commandment he was giving us is love. He wants us to love one another. love will always forgive. Love does not keep any score of wrong. Love does not remember the wrong things that others do to it. Love endures all and forgives all.
As believers in Jesus Christ, we are to walk in love. When we walk in love it will be easy to forgive those who offend us. When we practice love we will not think evil about others. Love will not cause offenses. As Bro Eli Soriano noted, it is because people are not walking in love that is why it is difficult for them to forgive each other. Let us put on the garment of love. Let us learn to keep as memories of wrong things.
Our God says that he will not remember our sins. He is a great God with a very big memory. He can forget anything. But he is able to forget the iniquities of those who truly repent. If God can forgive and forget, why is it difficult for us to forget what people do to us that is unpleasant? Let us learn to forgive our brethren out of love.