Dear Grace,
As a Catholic, I would like to have a better understanding of what infallibility means. When it is that we can say the pope teaches infallibly?

The word infallible literally means the “inability to err.” Therefore, “infallibility” is the word that the Catholic Church uses to refer to the charism (gift) which has been given by God to the Holy Father and the Magisterium (the teaching office of the Church – pope and bishops) under certain conditions. The mistake that many people make is in thinking that this means that the Pope cannot ever be wrong in anything or commit errors of any sort, including personal conduct. This is not what the Church teaches at all.

The official statement on infallibility can be found in the First Vatican Council’s Dogmatic Constitution on the Church of Christ (Pastor aeternus). Essentially, what it says is that when the Pope (1) intends to teach (2) by virtue of his supreme authority (3) on a matter of faith and morals (4) to the whole Church, he is preserved by the Holy Spirit from error. His teaching act is therefore called “infallible” and the teaching that he articulates is termed “irreformable” (Chap. 4, n. 9).

The evidence that papal infallibility is part of the Christian Faith comes to us from Sacred Scripture and the Sacred Tradition of the Church. This Tradition includes of course the witness of many of the early Fathers, those men of great faith who documented in their writings what was believed and practiced in the early Church.

When Peter recognized Jesus as the messiah, the Son of the living God, Jesus turned to him and declared, “I tell you, you are Peter, and on this rock I will build my Church, and the gates of the hell shall not prevail against it. I will give you the keys to the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Matthew 16: 18-19). He also instructed him to feed His lambs and tend His sheep (John 21: 15-17). It is quite clear from these passages that He meant for Peter to be in charge of His Church. Peter, who had made mistakes and shown weakness, was the one Christ chose.

Another interesting and revealing biblical passage that demonstrates the divine plan that Jesus had for Peter is the one in which He says, “Simon, Simon, behold Satan has demanded to sift all of you like wheat, but I have prayed that your faith may not fail; and once you have turned back, you must strengthen your brothers” (Luke 22: 31-32). Here, He was predicting Peter’s denial, and yet there is a definite indication that he will be preserved from error in order to strengthen the others, the rest of the Church.

He certainly knew that Peter was not perfect, that he had made mistakes and would continue to do so in the future. But when it came to matters of faith and morals (which are the matters that pertain to salvation), he would always have the assistance and guidance of the Holy Spirit. Surely Christ knew that Peter would always require this help; after all, he was a sinner who would constantly need God’s grace. Does it make any sense that Jesus would leave him in charge of strengthening the others and then allow him to fall into error in his teaching of the faith? Let us remember that He said the gates of hell would never prevail against His Church.

Infallibility does not mean that the Pope can teach without error on any subject he chooses. Only under the four conditions stated above can he be said to teach with a guarantee of freedom of error. In reality, only God alone is infallible. No man is perfect. When the Pope teaches infallibly, it is only because of the divine assistance from God, which we believe he has received. For our Holy Father, the direct successor of St. Peter, preserving the Church in the true faith is a tremendous task and responsibility, and that is why we should remember him in our prayers daily

This article taken from Grace's new book, Dear Grace: Answers to Questions About the Faith, now available in our online store! Faith questions may be sent to Grace via e-mail at: You may also visit her online at

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