Answer
In order to argue against Protestantism and Sola Scriptura, Roman Catholics will often ask, sarcastically, that if we are to only go by what the Bible says, not church tradition, which of the 30,000-plus Protestant denominations has the correct interpretation? The argument is essentially that, since the Reformation has resulted in thousands of denominations/divisions within Christianity, which is clearly not God’s desire, Sola Scriptura must be invalid and God must have established an infallible interpreter of Scripture; namely, the Roman Catholic Church, the first church, the one true church of God.
The “30,000 Protestant denominations” argument fails on several points. First, there are not 30,000 Protestant denominations. Even under the most liberal definition of what constitutes a denomination, there are nowhere close to 30,000 Protestant denominations. The only way to get even remotely close to the 30,000 figure is to count every minor separation as an entirely different denomination. Further, the vast majority of Protestant Christians belong to just a handful of the most common Protestant denominations; i.e., Baptist, Lutheran, Methodist, Presbyterian, Pentecostal, etc. Yes, it is undeniably sad that there are so many denominations, but the 30,000 Protestant denominations argument is an extreme exaggeration of the reality of the divisions within Protestantism.
Second, even if there genuinely were 30,000 Protestant denominations, one thing all Protestant denominations agree on is that the Roman Catholic Church is not the one true church of God. Protestant denominations are unanimous in rejecting the papacy, the supremacy of Rome, prayer to saints/Mary, worship of saints/Mary, transubstantiation, purgatory, and most other Roman Catholic dogmas. Sola Scriptura has led all Protestant denominations to the same conclusion – the Bible does not teach many of the things Roman Catholics practice/believe. Further, outside of disagreeing with Roman Catholicism, the Protestant denominations agree on far more issues than they disagree on. Most of the Protestant denominations were formed because of a non-essential doctrine, a side issue, on which Christians can agree to disagree. As an example, Pentecostalism separated from the other denominations based primarily on the issue of speaking in tongues. While tongues can be an important issue in the Christian life, in no sense does it determine the genuineness of faith in Christ.
Third, there is no infallible interpreter of Scripture, nor is there a need for one. There is no infallible denomination or church. Even after receiving Christ as Savior, we are all still tainted by sin. We all make mistakes. No denomination/church has absolutely perfect doctrine on every issue. The key is this – all the essentials of the faith are abundantly clear in God’s Word. We do not need an infallible interpreter or 2,000 years of church tradition to determine that there is one God who exists in three Persons, that Jesus died for our sins and was resurrected from the dead, that Jesus is the one and only way of salvation, that salvation is received by grace through faith, that there is an eternal heaven awaiting those who trust in Christ and an eternal hell for those who reject Him.
The core truths that a person needs to know and understand are absolutely and abundantly clear in Scripture. Even on the non-essentials, if Sola Scriptura were consistently applied, there would be unanimity. The problem is that it is very difficult to perfectly and fully apply Sola Scriptura, as our own biases, faults, preferences, and traditions often get in the way. The fact that there are many different denominations is not an argument against Sola Scriptura. Rather, it is evidence that we all fail at truly allowing God’s Word to fully shape our beliefs, practices, and traditions.