"Go first and be reconciled with your brother"
God has ordained that men should dwell peaceably and of one accord with each other, that they should live “of one mind in his house” (Ps 67,7 Vulg.). He desires that, once reborn in baptism, we should persevere in that condition in which our second birth has placed us. He desires that, since we are children of God, we should remain in God’s peace and that, since we have received the one Spirit, we should live in unity of heart and mind.
This is the reason why God does not receive the sacrifice of the man who lives in dissension. He decrees that we should leave the altar to be reconciled first of all with our brother so that God may accept the prayers offered to him in peace. The greatest sacrifice we can offer to God is our peace; it is fraternal harmony; and it is a people gathered together by that unity which exists between Father, Son and Holy Spirit.
~Blessed Alan de la Roche