The Catholic Church affirms that under certain conditions the Pope, the Bishops, and in a certain way the Church herself exercises a gift of infallibility. This is a stumbling block for most Protestants. Why is this dogma so important that the Church insists upon it despite the obvious difficulties it creates for ecumenical efforts with those who deny that ecclesial infallibility exists?
The Catechism explains it this way:
In order to preserve the Church in the purity of the faith handed on by the apostles, Christ who is the Truth willed to confer on her a share in his own infallibility. By a “supernatural sense of faith” the People of God, under the guidance of the Church’s living Magisterium, “unfailingly adheres to this faith.” (CCC §889)
The purpose of Christ’s gift of infallibility to the Church is the preservation of the truths of the Faith.
Protestants will generally complain that this gift was not only not given but that it is unnecessary. Why? Because God gave us the Bible. The Bible, they say, is inerrant and consequently satisfies the needs that Catholics say are fulfilled by the gift of infallibility. For its part the Church says that the Bible by itself is insufficient. Here’s why.
The best way to look at this question may be with a parallel sort of example: The U.S. Constitution. Final interpretive authority for the Constitution has been vested in the Supreme Court. When there is a difference of opinion about the meaning of the Constitution, or of how (or whether) it applies in some case or other, the Supreme Court’s decisions about that meaning and application are final. Now, consider what would happen if there was no final interpretive authority for the Constitution.
The result seems entirely obvious: social (or at least judicial) chaos would ensue. If we didn’t have a Supreme Court, we would have to invent one so as to restore some kind of order in our communities. For example, we would have camps opposing and favoring private gun ownership, abortion, and dozens of other social and cultural issues, and with no way of finally settling the differences. Each group would appeal to the Constitution in defense of its views, but the absence of a final interpretive authority would make resolution impossible in at least some cases.
The point, of course, is that books and documents do not tell us their meanings themselves. They have to be interpreted. And unless there is a final, ultimate interpretive authority to settle the disagreements, the best that can be hoped for are attempts at consensus with varying degrees of success and accuracy.
And that is the point of the infallibility of the Church: to preserve the purity of the Faith through the ages, God was pleased to grant the gift of infallibility to the Church in certain circumstances. If we want to see what happens when that authority is denied, it is not hard to find. We need look no further than the plethora of Protestant ecclesial communities who cannot agree on what truths the Bible teaches as essential. We need the infallibility of the Church so that we can know objectively what truths God has revealed, and hold them firmly because we love Him and want to know Him better.