The following is taken from ProtestantErrors.com with permission.
To those who say the true Church can err:
The Protestant reformers such as Calvin and Beza claim the Catholic Church to have been the True Church during the early centuries of Christianity (before they claim it fell into error). During those five hundred years the Church had fought and condemned the same doctrines that the Protestant reformers were resurrecting. Yet now Calvin and Beza have the audacity to offer the same doctrines again as medicine and holy reformations? If when the True Church in the early centuries of Christianity declared those Protestant beliefs to be error, how can the Protestant reformers now claim them to be truth and to base their new churches on them?
If the Church can err, to whom shall we have recourse in our difficulties? Protestants will say Scripture. We do not doubt that we must believe in and consult Scripture, but what if our difficulty pertains to Scripture itself? How can we find an answer? I cannot go to Luther or Calvin for they have opposing opinions. Do you really think Our Lord went to the trouble to establish His Church just to leave us in anarchy with no recourse on matters which could lead us into darkeness?
All denominations shout their claims with equal assurance that their interpretation of Scripture is accurate, which would leave all others inaccurate. To say Our Lord has not left us any guides to help us choose the good from the bad in an environment that He knew contained much error, is to say that He wishes us to be confused, which we know He does not.
Our Lord said, “And if he will not hear them: tell the church. And if he will not hear the church, let him be to thee as the heathen and publican” (Matt 18:17). How else can this be understood than Our Lord sends us to the Church in our differences? (If not the One, Holy, Catholic and Apostolic Church, which Protestant one?)
If the Church can err, and God commands us to go to the Church, then this means God wishes to deceive us. Does it make sense that God would send all of His lambs to the slaughter by commanding them to consult a Church that can contain error?
When St. Paul says, “But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth” (1 Timothy 3:15), why would he call the Church the “pillar and ground of truth” if it could contain error? (Why didn’t He call the Bible the pillar and ground of Truth?)
If the Church did err and the Protestant reformers started churches of their own, as they did, then how can we explain this verse from Scripture: “And he hath subjected all things under his feet, and hath made him head over all the church” (Ephesians 1:22). This verse refers to Jesus being head of ONE church, not multiple churches such as those started by Lutheran, Calvin and subsequent Protestants.
It must be made clear here that when we refer to the Church not erring, we are referring to the Church not misguiding the faithful with respect to faith and morals, which we are required to hear and know for our salvation. The Church at the same time is also a human society because it consists of human members. This is why scandals, heresies, schisms and sins among its members also arise. These sins are expected with human beings and do not indicate a failure of a divinely founded Church that Our Lord promised would never fail! Did the mission of all the Apostles fail or cease to be because Judas turned to betrayal? Of course not. Christ Himself foretold of these type of problems in Scripture when He spoke parables in Matthew 13 regarding the wheat and tares and the net containing good fish and bad fish. Consider the verses,
“Again the kingdom of heaven is like to a net cast into the sea, and gathering together of all kind of fishes. Which, when it was filled, they drew out, and sitting by the shore, they chose out the good into vessels, but the bad they cast forth. So shall it be at the end of the world. The angels shall go out, and shall separate the wicked from among the just.” Matthew 13:47-49.
In summary, Our Lord said His Church would never fail, yet we clearly see members of His Church making mistakes due to their human natures. These mistakes clearly do not indicate failure of the Church. Again, the Church is equivalent to an army with good and bad soldiers, many of which stray or are killed, but this does not affect the army as a whole. The same applies to the true Church of Christ; it continues unscathed over the gates of hell despite the downfalls of its members.