And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven" (Matt. 16:13-20)
The Gospel this Sunday is from St. Matthew Jesus, the true Son of God, became man in order to make all men His brothers and co-heirs with Him, to the divine, eternal kingdom. To carry on His divine mission on earth (after He had ascended into heaven), He founded the Church on the twelve Apostles. This Church was to be God's new Chosen People. It was to be made up of all races from all parts of the world. As its mission was to bring the message of salvation to all men, it was to go on until the end of time. For this Church, this divinely instituted society of human beings, to carry out its mission of helping all men to reach their eternal kingdom, it was necessary to be sure of the road and the aids offered to its members. In other words, the Church should be certain that what it told it’s people to believe and to practice was what God wanted them to believe and to practice.
Today's reading from St. Matthew tells us how Christ provided for this necessity. In making Peter the head of the Apostolic College, the foundation-stone of his Church, the guarantor of its stability in the symbol of the keys and the promise that all his decisions would be ratified in heaven, Christ gave him the power of freedom from error when officially teaching the universal Church.
In other words, Peter received the primacy in the Church and the gift of infallibility in his official teaching on matters of faith and morals. As the Church was to continue long after Peter had died, it was rightly understood from the beginning that the privileges given to him and which were necessary for the successful mission of the Church, were given to his lawful successors-the Popes.
This has been the constant belief in the Church from its very beginning. The first Vatican Council solemnly defined this dogma and it was reconfirmed recently in the second Vatican Council. In giving these powers to Peter and to his lawful successors Christ was planning for our needs. In order to preserve and safeguard the right conduct of all its members He provided a central seat of authoritative power in His Church. Through the gift of infallibility He assured us that whatever we were commanded to believe (faith) or to do (morals) would always be what He and his heavenly Father wanted us to believe and to do.
O God, who cause the minds of the faithful to unite in a single purpose, grant your people to love what you command and to desire what you promise, that, amid the uncertainties of this world, our hearts may be fixed on that place where true gladness is found.