Question: I am a Reformed Christian, but I have the following question: since Jesus said in Matthew 16:18 that the Church would always exist, and Catholicism is heretical, where was the Church before the Reformation? I understand that the Church does not need to be visible, that is, an organization, but in most of the articles I have read, the answer to this question would be that there were people who opposed the ideas of Catholicism, but they were always isolated thinkers or groups that equally had heretical ideas, as far as I know.
Answer: Greetings and thank you for your interesting question. Let me begin by saying that I am a pastor in a Reformed church, so this question is near and dear to me.
Let me begin by saying that in Matthew 16:18, Jesus said a little more than just that the church "would always exist." He said, "And I also say to you that you are Peter, and on this rock I will build My church, and the gates of Hades shall not prevail against it" (Matthew 16:18 NKJV). Jesus is building His church, and when He says, "the gates of Hades shall not prevail," He is saying that the church of Jesus Christ will storm the gates of her enemies and prevail. Be that as it may, your point is valid. Since Jesus is building His church, it will always exist.
Now, regarding your point that "Catholicism is heretical," I believe we need to be precise in our language, so as to avoid being misunderstood. "Catholicity," which simply means universal, is one of the four qualities of the church of Jesus Christ that is codified in the ecumenical creeds of the church (Apostles', Nicene, Athanasian). We confess and believe the church to be one, holy, catholic, and apostolic. In contrast to the people of God in the OT, which was contained (primarily) to the nation of Israel, the people of God in the NT is comprised of people from every tribe, tongue, and nation. In a word, "catholic." So while I know your term "Catholicism" is shorthand for "Roman Catholicism," I want to make sure we don't confuse the issue. The word "catholic" is a perfectly good word and describes the nature of the church of Jesus Christ.
With that said, I would still be careful in saying "Roman Catholicism is heretical." While it's hard to pinpoint the exact moment when the Roman Catholic Church (RCC) began, we can say with some confidence that it was during the ancient period of church history. Of course, the RCC would say their origin dates back to the formative statement in Matthew 16:18, but I believe the consensus of church history would deny that claim. We know that in the post-apostolic period, as the church began to grow, there were large urban areas that became important centers of church activity. You had Jerusalem, Antioch, Alexandria, Constantinople, and Rome. The bishops (overseers) of these cities were prominent, but they were seen more as colleagues, a group of equals. As time went on, the bishop of Rome began to assert primacy over the other "sees" (Latin for "seat"). The main basis for this claim was what is called the "Petrine theory" (Petrine = pertaining to Peter). Tradition has Peter, along with Paul, being martyred in Rome during the reign of Nero. That along with Jesus' statement in Matthew 16:18 on building the church on the "rock" of Peter (which means "rock"). Another reason for the rise of the Roman see came during the fall of the (western) Roman Empire in the 5th century. It was Pope Leo I who met with Attila the Hun and convinced him to not sack Rome. As the political power of the empire fell, the power of the Roman bishop began to rise to fill the void. In the 6th century, you begin to hear claims of papal supremacy. It wasn't until the Second Council of Lyon (1274) that the church officially declared the primacy of the bishop of Rome.
Another interesting fact of church history is the development of orthodox doctrine. It's not as if when the apostles left the scene that the church had a well-defined system of doctrine. Doctrine develops usually as a result of responding to heresy. Christians of all varieties (Roman Catholic and Protestant) affirm the first four ecumenical councils: Nicaea (325), Constantinople (381), Ephesus (431), and Chalcedon (451). These first four councils articulated what all Christians now believe regarding the Trinity and the person of Jesus Christ. These councils answered the false claims of heretics such as Arius, Nestorius, and others. All of these ancient heresies formed in what was, at that time, the eastern part of the church (usually in Alexandria). Rome was on the side of orthodoxy in each of these early church debates.
Why do I mention all of this? Because it's incorrect to say that Roman Catholicism has always been heretical from day one. Moreover, since the formation of doctrine develops over time and usually in response to heretical teaching, official statements of church doctrine appear throughout the history of the church. Of course, there are teachings and practices going on in the church that either become incorporated into official church doctrine, or rejected. Take, for example, the doctrine of transubstantiation. The doctrine of transubstantiation wasn't formally affirmed until the Fourth Lateran Council (1215), even though the practice had been engaged throughout the church. Even with that, there have always been segments of the church that did not agree with full-blown transubstantiation, both before and after Fourth Lateran.
As children of the Protestant Reformation, the reason why we believe that the RCC is heretical is because of its formal denial of sola fide, or "faith alone." The early Protestant reformers held to sola Scriptura, sola gratia, and sola fide. We are saved by grace alone through faith alone on the authority of Scripture alone. It is often said that the material cause of the Reformation was sola fide and that the formal cause of the Reformation was sola Scriptura. It's not that Rome denied salvation by grace through faith, it's the alone that they objected to. Similarly with Scripture. Rome does not deny the authority of Scripture. They deny the alone part because they want to uphold unwritten church tradition as equal to the authority of Scripture. However, it wasn't until the Council of Trent (1545-63) that they anathematized (pronounced as cursed) those who believe in the doctrine of sola fide (Canon XIV of the Council of Trent). If you want a point in time when the RCC apostatized, I would pick this point for it is a denial of what we believe to be the gospel. As Paul says, "But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed" (Galatians 1:8 NKJV).
Again, it's hard to say with any certainty that the RCC has always believed what it codified during the Council of Trent. The RCC, despite their own claims, is not a monolithic organization theologically speaking. As I have tried to highlight, there have always been those who are faithful within the RCC, even now. It's like what the LORD said to Elijah, "Yet I have reserved seven thousand in Israel, all whose knees have not bowed to Baal, and every mouth that has not kissed him" (1 Kings 19:18 NKJV). It would be incorrect to say that the church was "invisible" until the time of the Reformation. It would be incorrect to say that the RCC was heretical throughout her long history. It would be correct to say that the RCC officially abandoned the gospel when they denied sola fide, and since the RCC still affirms the teaching of Trent, it is apostate to this day. Even with this, I am sure there is a remnant of God's people within the RCC. Just as I am sure that are heretics and apostates in Protestant & Reformed churches who would "affirm" sola fide.
So, where was the church before the Reformation? The church of Jesus Christ has always existed before, during, and after the Protestant Reformation. The reason this is so is because it is Jesus Christ who is building His church, not popes, not reformers, etc.
