Q. Non-Catholic friends of mine have asked me about the pope being infallible. I’m not sure how to explain it to them. And how many times has it actually been used?
The bottom line is that one of the uses of this authority is to teach us the truth without error! This authority to teach the truth is deeply intertwined with our understanding of the infallibility of the pope! That doesn’t mean the pope can tell us when the Cubs will win the World Series, instead, it means that anything that the pope teaches regarding our life of faith or morals is the truth. And when he speaks definitively, it’s infallible!
Why does the pope have this authority? Because, as those young people at World Youth Day understood, the “keys to the kingdom,” given to St. Peter by Jesus, have been passed on from him to all of his successors. There is an unbroken line of succession from Peter to the present Pope. So Peter, and his authority to “bind and loose,” is still alive in our Church today in the person of the Holy Father.
As for your second question, “how many times has it actually been used,” it’s not really a black and white answer. Some would say that the pope has only exercised this once, in 1950, when he proclaimed that our Blessed Mother was taken body and soul into heaven when her life on earth was complete.
But in truth, the infallible authority of the pope, and the Church itself, has been exercised in an ordinary way countless times. In fact, every time that the pope teaches us, or any time the pope and the bishops teach us together, such as in Vatican II, we can be certain that what they teach us is true. This all stems from that authority Jesus gave Peter when he gave him the “keys to the kingdom of heaven!”
If this is confusing, or too much for you to try and explain to your friend, just pray for greater understanding and pray for your friend. Ultimately, it’s only the Holy Spirit who can teach us what this all means.