Does the Bible itself identify specific doctrines as fundamental? Indeed it does. In fact, if the strongest words of condemnation in all the New Testament are reserved for false teachers who corrupt the gospel, then the gospel message itself must be acknowledged as a primary point of fundamental doctrine.

But what message will determine the content of our testimony? It’s a choice between divine revelation, and human speculation and opinion; between Scripture alone, and papal hierarchy and church tradition. The two gospels are flatly contradictory and mutually exclusive.

Those considerations determine what message we proclaim and whether that message is the authentic gospel of true Christianity. We are clearly dealing with matters that go to the very heart of the doctrines Scripture identifies as fundamental.

Can we get more specific? Let’s turn to Scripture itself and attempt to lay out some biblical principles for determining which articles of faith are truly essential to authentic Christianity.

Fundamental Doctrines Come from Scripture

First, 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 19:7a). 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.

This, of course, is the Reformation principle of sola Scriptura—Scripture alone. It contrasts starkly with the practice of the Roman Catholic Church, which 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” [Francis Turretin, Institutes of Elenctic Theology, vol. 1, George Musgrave Giger, trans. (Phillipsburg, N.J.: Presbyterian & Reformed, 1992),53].

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 that is genuinely fundamental apart from Scripture.

Fundamental Doctrines Are Clear in Scripture

Second, if we’re to regard an article of faith as fundamental, it must be clearly set forth in Scripture. No “secret knowledge” or hidden truth-formula could ever qualify as a fundamental article of faith. No key is necessary to unlock the teaching of the Bible.

The truth of God is not aimed at learned intellectuals; it is simple enough for a child. “Thou didst hide these things from the wise and intelligent and didst reveal them to babes” (Matthew 11:25, KJV). The Word of God is not a puzzle. It does not speak in riddles. It is not cryptic or mysterious. It is plain and obvious to those who have spiritual ears to hear. “The testimony of the Lord is sure, making wise the simple” (Psalm 19:7b).

The point is not that every fundamental article of faith must be supported with an explicit proof text. The doctrine of the Trinity, for example, is certainly essential to true Christianity—and it is very clear in Scripture—but you will find no comprehensive statement of the Trinity from any single passage of Scripture.

Witsius wrote,

Among articles clearly contained in the Scriptures … we must include not only those which they teach in express words, but also those which, to all who apply their minds to the subject, are obviously deducible from them by necessary consequence. Our Lord and his Apostles very frequently confirmed even fundamental articles of faith by consequences deduced from Scripture [cf. Luke 20:37–38]… The knowledge of a fundamental article consists not in understanding this or the other passage of the Bible; but in an acquaintance with the truth, which in one passage, perhaps, is more obscurely traced, but is exhibited in other places in a clear, nay, in the clearest possible light. [Herman Witsius, Sacred Dissertations on the Apostles’ Creed, 2 vols. (Phillipsburg, N.J.: Presbyterian & Reformed, 1993 reprint), 1:21]

Nor does this mean that a doctrine must be non-controversial in order to be considered a fundamental article. Some would argue that the only test of whether something is essential to true Christianity is whether it is affirmed by all the major Christian traditions. But as Witsius points out, according to that rule, hardly anything of any substance would remain to distinguish the Christian gospel from the “salvation” offered by pagan morality or Islamic theology. “There is much truth in the remark of Clement of Alexandria; ‘No Scripture, I apprehend, is so favourably treated, as to be contradicted by no one’” (Witsius, 1:21).

There are three more guidelines to help us determine fundamental doctrines. We’ll get to those next time.For now, here’s a question to discuss in the comment thread: If a fundamental doctrine is clear in Scripture, does that mean it’s easy to comprehend? Why or why not?