Christ Giving the Keys to St. Peter, fresco by Pietro Perugino

Infallibility: What’s the Big Deal?

The big deal is oneness. Jesus established His one Church. If that Church is to remain one – if there are not to be splits into multiple churches – there must be some authority who can settle the inevitable disputes in doctrinal interpretation.

This fact is very evident when you look at other Christian denominations. There are literally thousands of denominations that now exist. Jesus knew this would be a problem. That is why when He declared Peter to be the rock upon which He would build His Church, He went on to say, “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.”

We proclaim our Church to be “one, holy, catholic, and apostolic”. We thank God for the gift of infallibility He gave the Pope and Magisterium which has kept His Church one through the centuries.


In 1870, the first Vatican Council declared the doctrine of Infallibility of the Pope, (and the Pope in union with the Magisterium) to exist when he: (1) intends to teach (2) by virtue of his supreme authority (3) on a matter of faith and morals (4) to the whole Church. When all four of these conditions apply, the Pope is preserved by the Holy Spirit from error. The teaching act which he articulates is termed “irreformable”, meaning not subject to revision.

Though infallibility was not formally declared until 1870, it has always been accepted. As evidence, during the first few hundred years of Church history, many who were accused of heresy appealed from every corner of the known world to the pope in Rome for vindication or condemnation. Also, the popes always had the decisive word at general councils. For example, at the Council of Chalcedon in 451, after reading Pope Leo’s epistle defining the two natures of Christ as True God and Man, the bishops declared, “Peter has spoken through Leo” – and accepted it unhesitatingly.

Is It Biblical?

We have presented Biblical quotes from the Gospels wherein Jesus declares Peter as the Rock and declares that the gates of Hell shall not prevail against His Church. So it would seem that Biblical support is evident. Yet some apologists argue strongly that Papal Infallibility is NOT Biblical.

Perhaps the most common argument is that the Catholic Church needed to declare infallibility in order to keep Catholics from reading the Bible. According to this argument, if the Church gives members the infallible interpretation, they won’t waste their time actually reading the Bible. And, if Catholics don’t actually read the Bible, they won’t discover all the errors in the teachings and traditions of the Church.

There is not sufficient space here to counter this argument at length. However: 1) The Church encourages Catholics to read and study the Bible. 2) When we read the Bible, we find support for infallible doctrines, (such as the Immaculate Conception), from Genesis to Revelation. 3) The Bible itself states the importance of following traditions not necessarily spelled out in the Bible when Paul says, “Therefore, brothers, stand firm and hold fast to the traditions that you were taught, either by an oral statement or by a letter of ours.” 2 Thes 2:15


Infallibility is a gift from God given to preserve His Church as one.

Infallibility does NOT mean the Pope and Bishops are perfect. Catholics are not bound to hold as true everything the Pope or a Bishop says at any time, on any topic. Rather, Infallibility is given to the Pope and the Magisterium when all of the following apply: when teaching, by virtue of supreme authority, on matter of faith or morals, to the whole Church.

When the Pope, or the Magisterium in union with the Pope, makes an infallible declaration, we, the faithful, are obliged to believe the declaration. That declaration cannot be reformed.

Papal Infallibility has been recognized by the Church from its earliest days, though it was only declared formally in 1870.

Infallibility is Biblical.

Fact Sheet