Following the Dark Ages, the early Reformers took up the mantle of fighting for the Christian fundamentals. The five solas of the Reformation represented the fundamental doctrines that they saw as non-negotiable. Sola gratia declares that salvation is by God’s grace alone in defiance of the Catholic belief in grace plus works. Sola fide and sola Christus assert that salvation is appropriated by faith alone in Christ alone and apart from any human works (rejecting Mary as a co-redemptrix). Soli deo gloria reminds us that everything we do should be done to the glory of God alone. Those four solas roar with exclusivity and are pillars that uphold the structure of sound doctrine. But the fifth sola is the foundation of them all.

Sola Scriptura affirms that Scripture is the exclusive authoritative source of truth. It was the Reformers’ chief battle cry against the presumptuous and artificial authority of the Roman Catholic Church. Scripture is the only revelation from God to man. It does not share its authority with the church, nor is it subject to the authority of the church.

God’s Word is the inerrant revelation of all fundamental Christian truth. But does the Bible itself identify which doctrines are fundamental? In his book Reckless Faith, John MacArthur answers with an emphatic yes: “The strongest words of condemnation in all the New Testament are aimed at false teachers who corrupt the gospel.”^[1] John MacArthur, Reckless Faith (Wheaton: Crossway, 1994) 108. Paul pronounced damnation on anyone who rewrote the message of salvation by grace through faith in Jesus Christ:

But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed! As we have said before, so say I again now, if any man is preaching to you a gospel contrary to what you have received, he is to be accursed! (Galatians 1:8–9).

According to John MacArthur, the implication of Paul’s condemnation is clear: “Therefore the gospel message itself must be acknowledged as a primary point of fundamental doctrine.”^[2] Reckless Faith, 108. That, in turn, helps us understand a key characteristic of all fundamental doctrines. As John explains:

If a doctrine is truly fundamental, it must have its origin in Scripture, not tradition, papal decrees, or some other source of authority. Paul reminded Timothy that the Scriptures are “able to make thee wise unto salvation” (2 Timothy 3:15, KJV). In other words, if a doctrine is essential for salvation, we can learn it from the Bible. The written Word of God therefore must contain all doctrine that is truly fundamental. It is able to make us “adequate, equipped for every good work” (2 Timothy 3:17). If there were necessary doctrines not revealed in Scripture, those promises would ring empty.

The psalmist wrote, “The law of the Lord is perfect, restoring the soul” (Psalm 19:7). That means Scripture is sufficient. Apart from the truths revealed to us in Scripture, there is no essential spiritual truth, no fundamental doctrine, nothing essential to soul-restoration. We do not need to look beyond the written Word of God for any essential doctrines. There is nothing necessary beyond what is recorded in God’s Word.^[3] Reckless Faith, 109.

That encapsulates sola Scriptura. Any doctrine that is antithetical or supplementary to Scripture violates the exclusivity of God’s Word. And that is the realm in which the Roman Catholic Church has operated for centuries:

The Roman Catholic Church . . . commonly threatens eternal damnation for anyone who questions the decrees of the Pope or the dogma of Church Councils. For example, Canon 1 of the seventh session of the Council of Trent pronounces anathema on anyone who says that there are more or less than the seven Sacraments established by the Council. That means if any Catholic questions the sacraments of Confirmation, Penance, or Extreme Unction—mentioned nowhere in Scripture—that person is subject to excommunication and in the Church’s eyes is worthy of eternal damnation. The Canons and Decrees of the Council of Trent are larded with similar anathemas—in effect making all the Council’s dictums fundamental doctrines. In Francis Turretin’s words, they “are impudent enough often to declare as fundamental their own hay and stubble and whatever the Romish church teaches.”

But according to the Bible itself, no supposed spiritual authority outside “the sacred writings” of Scripture can give us wisdom that leads to salvation. No papal decrees, no oral tradition, no latter-day prophecy can contain truth apart from Scripture that is genuinely fundamental.^[4] Reckless Faith, 109–110.

In a world full of subjective opinions and claims of truth, the Bible objectively declares God’s truth. Why build our lives on false religions when God has provided a foundation of fundamental doctrine? Sola Scriptura establishes the source of all fundamental Christian truth.

Now that we know the exclusive source of truth, it raises a critical question: Is the extraction of fundamental biblical truth the exclusive domain of Bible scholars? Or has God spoken with enough clarity for the layman as well? That’s the issue we’ll address next time.