How can a Christian determine which doctrines are essential and which are not?
To begin with, the strongest words of condemnation in all the New Testament are aimed at false teachers who corrupt the Gospel. Therefore the Gospel message itself must be acknowledged as a primary point of fundamental doctrine.
But what message will determine the content of our gospel testimony? 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.
I. All Fundamental Articles of Faith Must Be Drawn from the Scriptures
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 19:7). 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.
This, of course, is the Reformation principle of sola Scriptura -- Scripture alone. 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.
II. The Fundamentals Are Clear in Scripture
Second, if an article of faith is to be regarded 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 cryptic 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 19:7).
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.
This does not 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. By 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.’” (Herman Witsius, Sacred Dissertations on the Apostles’ Creed [Phillipsburg, NJ: Presbyterian & Reformed, 1993 reprint], 1:21)
III. Everything Essential to Saving Faith Is Essential
Third, a doctrine must be regarded as fundamental if eternal life depends on it. Scripture is full of statements that identify the terms of salvation and the marks of genuine faith.
“Without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who seek Him” (Hebrews 11:6). That verse makes faith itself essential to a right relationship with God. It also expressly identifies both the existence and the veracity of God as fundamental articles of the Christian faith.
Elsewhere we are told that eternal life is obtained through the knowledge of the true God and Jesus Christ (John 17:3; 14:6; Acts 4:12). Since Jesus Himself is the true God incarnate (1 John 5:20; John 8:58; 10:30), the fact of His deity (and by implication the whole doctrine of the Trinity) is a fundamental article of faith (see 1 John 2:23). Our Lord Himself confirmed this when He said all must honor Him as they honor the Father (John 5:23).
The truths of Jesus’ divine Sonship and Messiahship are also fundamental articles of faith (John 20:31).
Of course, the bodily resurrection of Christ is a fundamental doctrine, because 1 Corinthians 15:14 tells us, “If Christ has not been raised, then our preaching is vain, your faith also is vain.”
Romans 10:9 confirms that the resurrection is a fundamental doctrine, and adds another: the lordship of Christ. “If you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you shall be saved.”
And according to Romans 4:4-5, justification by faith is a fundamental doctrine as well: “Now to the one who works, his wage is not reckoned as a favor, but as what is due. But to the one who does not work, but believes in Him who justifies the ungodly, his faith is reckoned as righteousness.” In other words, those who seek acceptance before God on the ground of their own righteousness will find they fall short (Romans 3:27-28; Galatians 2:16-3:29). Only those who trust God to impute Christ’s perfect righteousness to them are accounted truly righteous. This is precisely the difference between Roman Catholic doctrine and the Gospel set forth in Scripture. It is at the heart of all doctrine that is truly fundamental.
In fact, an error in understanding justification is the very thing that was responsible for the apostasy of the Jewish nation: “For not knowing about God’s righteousness, and seeking to establish their own, they did not subject themselves to the righteousness of God” (Romans 10:3). Is that not the precise failure of Roman Catholicism? But “Christ is the end of the law for righteousness to everyone who believes” (v. 4).
IV. Every Doctrine We Are Forbidden to Deny Is Fundamental
Certain teachings of Scripture carry threats of damnation to those who deny them. Other ideas are expressly stated to be affirmed only by unbelievers. Such doctrines, obviously, involve fundamental articles of genuine Christianity.
The apostle John began his first epistle with a series of statements that establish key points of the doctrine of sin (hamartiology) as fundamental articles of faith. “If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth” (1:6). That condemns wanton antinomianism (the idea that Christians are under no law whatsoever) and makes some degree of doctrinal and moral enlightenment essential to true Christianity. A second statement rules out the humanistic notion that people are basically good: “If we say that we have no sin, we are deceiving ourselves, and the truth is not in us” (v. 8 ). And a third suggests that no true Christian would deny his or her own sinfulness: “If we say that we have not sinned, we make Him a liar, and His word is not in us” (v. 10).
First Corinthians 16:22 makes love for Christ a fundamental issue: “If anyone does not love the Lord, let him be accursed.” And a similar verse, 1 Corinthians 12:3, says that no one speaking by the Spirit of God can call Jesus accursed.
The truth of Jesus’ incarnation is also clearly designated a fundamental doctrine: “Every spirit that confesses that Jesus Christ has come in the flesh is from God; and every spirit that does not confess Jesus is not from God; and this is the spirit of the antichrist” (1 John 4:2-3). “For many deceivers have gone out into the world, those who do not acknowledge Jesus Christ as coming in the flesh. This is the deceiver and the antichrist” (2 John 7). Those verses by implication also condemn those who deny the Virgin Birth of our Lord, for if He was not virgin-born, He would be merely human, not eternal God come in the flesh.
And since those who twist and distort the Word of God are threatened with destruction (2 Peter 3:16), it is evident that both a lofty view of Scripture and a sound method of Bible interpretation (hermeneutics) are fundamental tenets of true Christianity.
V. The Fundamental Doctrines Are All Summed up in the Person and Work of Christ
Paul wrote, “No man can lay a foundation other than the one which is laid, which is Jesus Christ” (1 Corinthians 3:11). Christ Himself embodied or established every doctrine that is essential to genuine Christianity. Those who reject any of the cardinal doctrines of the faith worship a “christ” who is not the Christ of Scripture.
How are the fundamentals of the faith personified in Christ?
With regard to the inspiration and authority of Scripture, He is the incarnate Word (John 1:1, 14). He upheld the written Word’s absolute authority (Matthew 5:18). Christ Himself established sola Scriptura as a fundamental doctrine when He upbraided the Pharisees for nullifying Scripture with their own traditions: “Rightly did Isaiah prophesy of you hypocrites, as it is written, ‘This people honors Me with their lips, but their heart is far away from Me. But in vain do they worship Me, teaching as doctrines the precepts of men.’ Neglecting the commandment of God, you hold to the tradition of men.… You nicely set aside the commandment of God in order to keep your tradition” (Mark 7:6-9). Our Lord had much to say about the authority and infallibility of the Word of God.
In the doctrine of justification by faith, it is Christ’s own perfect righteousness, imputed to the believer, that makes the pivotal difference between true biblical justification and the corrupted doctrine of Roman Catholicism and the cults. That is what Paul meant when he wrote, “Christ is the end of the law for righteousness to everyone who believes” (Romans 10:4). It is also why Paul wrote that Christ is become to us righteousness (1 Corinthians 1:30), and it is why Jeremiah called Him “The Lord our righteousness” (Jeremiah 23:6). The Lord Himself, Jesus Christ, is our righteousness (Jeremiah 33:16). That is the very essence of justification by faith alone, sola fide.
Of course, all the fundamental doctrines related to the incarnation — the Virgin Birth of Christ, His deity, His humanity, and His sinlessness — are part and parcel of who He is. To deny any of those doctrines is to attack Christ Himself.
The essential doctrines related to His work — His atoning death, His resurrection, and the reality of His miracles — are the very basis of the Gospel (cf. 1 Corinthians 15:1-4; Hebrews 2:3-4). Reject them and you nullify the heart of the Christian message.
The fundamentals of the faith are so closely identified with Christ that the apostle John used the expression “the teaching of Christ” as a kind of shorthand for the set of doctrines he regarded as fundamental. To him, these doctrines represented the difference between true Christianity and false religion.
That is why he wrote, “Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son” (2 John 9). Far from encouraging union with those who denied the fundamental truths of the faith, John forbade any form of spiritual fellowship with or encouragement of such false religion (vv. 10-11).
It has not been my purpose here to attempt to give an exhaustive list of fundamental doctrines. Such a task is beyond the scope of this article. Furthermore, the attempt to precisely identify and number such a list of doctrines would be an extremely difficult thing to do. However, a reasonable list of fundamentals would necessarily begin with these doctrines explicitly identified in Scripture as non-negotiable: the absolute authority of Scripture over tradition (sola Scriptura), justification by faith alone (sola fide), the deity of Christ, and the Trinity.
But what are we to do with this understanding? First of all, we should resist any temptation to wield these doctrines like a judge’s gavel that consigns multitudes to eternal doom. We must not set ourselves up as judges of other people’s eternal fate.
On the other hand, we must recognize that those who have turned away from sound doctrine in matters essential to salvation are condemning themselves. “He who does not believe has been judged already” (John 3:18). Our passion ought to be to proclaim the fundamentals with clarity and precision, in order to turn people away from the darkness of error. We must confront head-on the blindness and unbelief that will be the reason multitudes will one day hear the Lord say, “I never knew you; depart from Me” (Matthew 7:23). Again, it must be stressed that those who act as if crucial doctrines were of no consequence only heap the false teacher’s guilt on themselves (2 John 11).
We have no right to pronounce a sentence of eternal doom against anyone (John 5:22). But by the same token, we have no business receiving just anyone into the communion and fellowship of the church. We should no more forge spiritual bonds with people whose religion is fundamentally in error than we would seek fellowship with those guilty of heinous sin. To do so is tantamount to the arrogance shown by the Corinthians, who refused to dismiss from their fellowship a man living in the grossest kind of sin (1 Corinthians 5:1-3).
We must also remember that serious error can be extremely subtle. False teachers don’t wear a sign proclaiming who they are. They disguise themselves as apostles of Christ (2 Corinthians 11:13). “And no wonder, for even Satan disguises himself as an angel of light. Therefore it is not surprising if his servants also disguise themselves as servants of righteousness” (vv. 14-15). In view of the current hunger for ecumenical compromise, nothing is more desperately needed in the church right now than a new movement to reemphasize the fundamental articles of the faith.