One of the foundational principles of the Protestant Reformation was that Sacred Scripture is the only valid source of Christian beliefs. Martin Luther made this one of his primary claims against the validity of Papal authority, purgatory, and many other Catholic teachings that had been held since the time of the apostles. Many Protestant denominations still cling to this belief.
There are several problems with this assertion. The first is that there is no basis for saying that Scripture alone is the authoritative source of Christian doctrine. Certainly there is no mention of this in Scripture itself. Secondly, this belief has caused many protestants to examine the Bible and through their own interpretation, claim that certain Catholic doctrines are in error. Thirdly, due to the lack of an authoritative source of interpretation of the Scriptures, we have seen the splintering of the Protestant denominations because each has its own interpretation of the Scriptures. We shall attempt to examine each of these issues in the light of Scripture and the Sacred Tradition of the Catholic Church in order to understand the problems associated with each.
First, when trying to understand the concept of Sola Scriptura, we would logically look for some basis for this belief in Scripture itself. We would be looking for a long time, because there is no evidence for it in the Bible. On the other hand, there are several passages in Scripture that show us that Sacred Scripture is to be understood in the light of Sacred Tradition. This Tradition, which has been handed down to us since the apostles, gives us a rich source of understanding of the words and intentions of Jesus. The first and most obvious verse to affirm the Catholic position on this matter is found in 2 Thessalonians 2:15, “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.” This verse clearly indicates the authority of oral tradition in forming doctrine.
Consider John 20:30, “Now Jesus did many other signs in the presence of (his) disciples that are not written in this book”. What about John 21:25? It states “There are also many other things that Jesus did, but if these were to be described individually, I do not think the whole world would contain the books that would be written.” These things that Christ did are handed down in the form of Sacred Tradition.
When Protestants interpret Scripture, they commonly claim that certain Catholic doctrines are against Scripture. This is what happens when Scripture is interpreted without guidance. One excellent example of a Catholic practice that is supposedly against Scripture is the sacrament of Confession. They claim that no man has the power to forgive sins. However, in John 20:23, Jesus says, “Whose sins you forgive are forgiven them, and whose sins you retain are retained.” This is clearly an indication of the validity of Catholic Confession. Protestants claim that the Bible does not affirm the authority of the Pope. They fail to consider the full passage in the Gospel of Matthew when making this claim, however. In Mt. 16:13-19, we have a dialog between Jesus and His disciples:
"Who do people say that the Son of Man is?" They replied, "Some say John the Baptist, others Elijah, still others Jeremiah or one of the prophets." He said to them, "But who do you say that I am?" Simon Peter said in reply, "You are the Messiah, the Son of the living God." Jesus said to him in reply, "Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father. And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. 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 see that the people had no idea what to believe. They thought Jesus may have been John the Baptist, or a prophet. They were seriously in error. Then there was Peter, who knew Jesus. He did not know Jesus because he heard it from someone else, but because the Holy Spirit guided him. This passage gives us the beautiful promise that Jesus made to us that He would never abandon His Church to confusion. He gave us a leader, Peter, who was the first Pope. We see that we need a moral leader who can speak with authority.
There are thousands of Christian denominations. Each one claims to have the truth. Logic dictates that only one religion can have the fullness of the truth. There is only one Truth, who is God Himself. Private interpretation of Scripture can be faulty, and this is even conveyed in the Bible. Acts 8:30-31 says, “Philip ran up and heard him reading Isaiah the prophet and said, ‘Do you understand what you are reading?’ He replied, ‘How can I, unless someone instructs me?’ So he invited Philip to get in and sit with him.” Here, the Bible clearly shows us the error of private interpretation of Scriptures. Philip sits down to guide the man through them so that they may be understood in the proper light.
These are just some of the reasons that Sola Scriptura, which is the belief that Scripture alone is the source for all Christian doctrine is wrong. We can only understand the Scriptures in the light of Sacred Tradition. The Bible itself does not dictate Sola Scriptura, but rather warns against it.