For I tell you, that unless your justice abound more than that of the scribes and Pharisees, you shall not enter into the kingdom of heaven. You have heard that it was said to them of old: Thou shalt not kill. And whosoever shall kill shall be in danger of the judgment. But I say to you, that whosoever is angry with his brother, shall be in danger of the judgment. And whosoever shall say to his brother, Raca, shall be in danger of the council. And whosoever shall say, Thou Fool, shall be in danger of hell fire. If therefore thou offer thy gift at the altar, and there thou remember that thy brother hath any thing against thee; leave there thy offering before the altar, and go first to be reconciled to thy brother: and then coming thou shalt offer thy gift. Be at agreement with thy adversary betimes, whilst thou art in the way with him: lest perhaps the adversary deliver thee to the judge, and the judge deliver thee to the officer, and thou be cast into prison.
Amen I say to thee, thou shalt not go out from thence till thou repay the last farthing.
Matthew 5:20-26 (Douay-Rheims Bible)
Dear Father it's easy to understand that not reconciling and correcting causes us much harm. Jesus was very open with this one in regard to how we are to let go. Reconcile with those we hurt and those who hurt us, but most of all to seek it with you. Don't we offend you the most by our actions and thoughts. We have not only a means to go to each other and bring forgiveness and seek it, we also have the Sacrament of Penance that we as Catholics rarely use. We are afraid our friends will see us and be judged by them. Our offense then is going up to the Altar with a multitude of transgressions on our souls. Each offense we commit when we go and receive with unclean hearts and souls the very life of your Son. We aren't giving you the gift of clean hearts then when we go up. Especially if we have any ill will toward our neighbor, toward you dear Father. We would think we have lost the reverence of the Mass in how we gather together and treat each other by our uncharitable natures. God sees everything, so why not seek the very place we will find cleansing before we give the gift of ourselves at Mass, the confessional and restore the luster of our garments.