Dear Bluegoat,
Cordial greetings.
The Catholic does know for a certainty that the Church is infallible and that it was established by our Lord upon St. Peter.
The Catholic Church bases its authority on the remarkable words “You are Peter, and on this rock I will build my Church…” (St. Matt. 16: 18). However, unlike Protestantism we do not simply make our appeal to the bible as if the mere citation of a text settles the matter conclusively without need for futher discussion. Rather, the line of argument which the Church adopts in validating her Divine origin and mission is as follows:
1/ The Church appeals, in the first instance, to the documents of the N.T., regarding them, not as as inspired books, but rather as genuine works of contemporary writers, in the same manner as she would appeal to Tacitus, Seneca, Josephus, or any other trustworthy historical authorities. In this way it is established, on the basis of purely historical evidence, that there was such a person as Jesus Christ; that He founded a Society, which received the names of Christian and the Catholic Church; that that Society has continued to exist down through the successive generations to the present time, and that the Catholic Church is that Society.
2/ Still regarding the N.T. writings only as regular historical records, the Church establishes the fact of the miracles of Christ and especially the miracle par exellence, His reported Resurrection. From thence the Church draws the inference that Christ must be God; either Christ was insane or was who He claimed to be, God. We can easily eliminate the possibility that He was mad, for no madman ever spoke the way that He did, neither did any sane man for that matter. In confirmation of His Divinity, and the truth of His mission, the Church appeals to the manner in which His prophecies concerning the Church and the Jewish nation have been fulfilled; to the global dissemination of the Gospel; to the constancy of the holy marytyrs; to the great change for the better that the proclamation of the Gospel has effected among mankind; and to the witness which the Church itself has borne, through so many generations, to the belief which has been held in the truth of His wondrous miracles.
3/ Having satisfactorily demonstrated that Christ is indeed God, His words must necessarily be Divine and thus infallibly true. However, it is on record that He uttered the words, “You are Peter…” (St. Matt. 16: 18); “As the Father has sent me, even so I send you” (St. John 20: 21); “Go therefore and make disciples of all nations…and behold, I am with you always, to the close of the age” (St. Matt. 28: 19,20). Now these being God’s words, the Church, to which they have reference, is indeed a Divine institution, and has authority from God Himself.
4/ This Church, founded by God, with a mission from God to teach the nations of the world, and equipped with a Divine promise that God will be with it to the final consumation of all things, cannot possibly err in its teaching on faith and morals; for it is, by God’s own appointment, infallible.
Warmest good wishes,
Portrait
Pax