One of the key principles of Protestantism that distinguishes it from Catholicism is sola scriptura, or “Scripture alone.”
Though it is interpreted differently among Protestants, it generally means that the Bible is either the highest or sole authority for Christians, superseding ecclesiastical authority and tradition.
The Catholic Church rejects sola scriptura, teaching instead that the Word of God is transmitted through both written Scripture and Sacred Tradition, and that the Church’s Magisterium is guided by the Holy Spirit to definitively and authoritatively interpret that Word for the faithful.
Here are three major problems with sola scriptura:
1) The Bible does not teach sola scriptura.
Where do Protestants derive the idea that the Bible alone is the highest authority for Christians? Is this taught anywhere in Scripture?
Actually, no. The verses to which Protestants usually point to answer this question indeed speak highly of the authority of Scripture and its importance for the people of God (e.g., Psalm 119, 2 Timothy 3:16-17, et al), but none of them say that the Bible alone is the only authority.
Not only that, but the Bible upholds the authority of oral tradition alongside Scripture in contradiction of sola scriptura.
In 2 Thessalonians 2:15, St. Paul writes:
“So then, brothers and sisters, stand firm and hold fast to the traditions that you were taught by us, either by word of mouth or by our letter.”
Here, Paul affirms that his teachings are authoritative whether delivered orally (tradition) or in writing (Scripture).
2) Sola scriptura cannot account for the origin of the Bible.
If the Bible is the only authority for Christians, then where did Christians get the Bible in the first place? Who determined what books should be in the Bible?
God did not deliver a fully compiled Bible from heaven. Rather, God inspired many different writers over the course of many centuries to write the various books of the Bible. The canon of the Bible was later definitively discerned and compiled by the Catholic Church in the fourth century, exercising apostolic authority and drawing upon Sacred Tradition to recognize which texts were inspired.
This means that the biblical canon itself depends on the very authority of oral tradition and ecclesiastical authority that sola scriptura rejects.
3) Sola scriptura does not work.
The Bible must be interpreted. Even when people think what the Bible says is clear, they are interpreting it. The problem is that different Christians often interpret the Bible in contradictory and mutually exclusive ways.
When that happens (and it happens constantly), how does the Christian church settle disagreements and safeguard the Gospel truth God has revealed in Jesus Christ?
If Christians cannot agree on the content of the Gospel, they cannot effectively fulfill their mission to proclaim it.
Sola scriptura offers no way out of these disagreements, except for Christians to split and go their separate ways – hence, myriad denominations. But this is a problem, too, because the Bible teaches that division among Christians is a sin (cf. 1 Corinthians 1:10ff).
The solution to this problem is the way of the very Catholic Church that Protestants reject, the way dating back to the early Church established by Jesus.
Jesus entrusted authority to the Apostles to teach and govern, and this authority has been handed down through apostolic succession to bishops in every generation. This authority does not supersede the Word of God—transmitted through Scripture and Tradition—but is guided by the Holy Spirit to faithfully preserve and interpret it.