Although apostolic doctrine was central to the life of the earliest churches, this centrality has not always been easy to preserve. Indeed, many of the great reforming moments that came later were really moments of recovery. Lost ways of doctrinal thinking and lost biblical doctrines were retrieved and made central once again. The reason for the church’s rather checkered history in this regard is quite simple: the content of this doctrine, as well as its function in the life of the church, is at the heart of the church’s spiritual warfare.
In the churches of John’s day, both “the Spirit of truth and the spirit of error” (1 John 4:6) were present. They are today, too. The Spirit of truth was heard in the apostolic teaching. Now it is heard through Scripture and through those who teach and expound that Scripture accurately. The spirit of error lives on in false teachers. The Spirit of truth and the spirit of error each have their respective audiences.
The false teachers troubling the Colossians, Paul says, were “promoting self-made religion” (Col. 2:23), conveyed in purely “human precepts and teachings” (Col. 2:22). It was false doctrine, an alternative to what is true. Nevertheless, it seemed wise. Others in that kind of audience are attracted to what is erroneous because of their “itching ears” (2 Tim. 4:3). They have a taste, even a need, for what is new and exciting (cf. Acts 17:21). And they cannot stand biblical truth. They will not tolerate “sound teaching” (2 Tim. 4:3; cf. 1 Tim. 1:6). Their criterion for accepting any teaching is not how well it accords with what the apostles taught or what we now have in Scripture, but how pleasing it is to them personally.
Perhaps there are some in this kind of audience who do not see the falsehood in false teaching because they are immature. They lack discernment. They are unstable in their understanding. Paul cautions us that we must “no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine” (Eph. 4:14; cf. Heb. 5:11–14).
Behind it all, though, are the dark designs of Satan. In life, his temptations are of many kinds and reach us in many different ways. With respect to what we should believe, some of these temptations come to us directly. There may be times, for example, when we doubt the truth of Scripture. Other temptations, though, come through false teachers. Paul says that in “later times” some people will slip away from their doctrinal foundations. Yet he immediately speaks of this not as some future yet to come but as a present reality already being experienced. Those giving up on apostolic teaching were, instead, “devoting themselves to deceitful spirits and teachings of demons” (1 Tim. 4:1; cf. 2 Tim. 3:1–17). Likewise, he worried that the Thessalonians, whom he had been unable to visit again, had given up on their faith—that is, the doctrine and practice they had been taught—because “somehow the tempter had tempted you” (1 Thess. 3:5; cf. 2:18). The reason Satan so tempts Christians is that biblical doctrine and its functioning are on the front line of his conflict with God.
Satan’s strategy, then, is to oppose, subvert, and mute the content of biblical doctrine and dislodge it from its place in the church’s life. God, though, has placed in the Christian’s hand a weapon for defense. It is the very truth under attack. It is what Paul calls the “belt of truth” and “sword of the Spirit” (Eph. 6:14, 17)—the Bible. These are parts of the Christian’s armor.
This explains a series of admonitions given in the NT that aim to protect the Bible’s doctrinal truth and secure its function in Christian life. Timothy must keep a close watch on himself and what he believes. He must persist in the truth of the apostolic doctrine. He is to “follow” this doctrine, that is, hold on to it, and “guard” it (2 Tim. 1:13–14). This is the “good [or beautiful] deposit” (2 Tim. 1:14). It is to be guarded as one would a precious jewel. It was “entrusted” to Timothy as it has been to us (1 Tim. 6:20). We are to “stand firm and hold to the traditions” (2 Thess. 2:15). Perhaps the image in Paul’s mind is that of a ship rolling and tossing in a storm and of sailors holding on to the sides or rigging to avoid being washed overboard. We must pay close attention to what has been taught, lest we drift away (Heb. 2:1). This original, apostolic teaching, and our confidence in it, must be held “firm to the end” (Heb. 3:14; cf. 1 John 2:24).
Christians, in other words, stay within the Bible’s doctrinal parameters. They are to persist in this doctrine, follow it, guard it, stand firm in it, and hand it on intact. They do not venture outside of it, for that is where faith becomes shipwrecked (1 Tim. 1:19–20). They resist its alternatives. They know this truth is entirely sufficient for life despite uncertainties and suffering. Later, of course, this truth was formulated into the Protestant principle of sola Scriptura.
It is the Bible’s truth that sustains, strengthens, and guides us. This is why Paul speaks of it as he does. It is, he says, made up of “sound words” (2 Tim. 1:13). It is “sound teaching” (2 Tim. 4:3) and “sound doctrine” (Titus 2:1; 1:9). It is in accord with the “sound words of our Lord Jesus Christ” (1 Tim. 6:3). This word, translated here as sound, is used also of physical health. Writing to Gaius, John prays that Gaius will be in “good health” (3 John 2). We encounter the same language in the Gospels. The man with a withered hand was healed so that the useless hand became “healthy like the other” (Matt. 12:13). People marveled when they saw Christ’s miracles, for they saw “the crippled healthy” (Matt. 15:31).
These references to “sound” teaching and doctrine, then, are a reminder to us that from such teaching the church’s strength arises. From it comes its health. It is what reverses spiritual ills and, sometimes, even deep paralysis. It is what makes churches whole. It is what lays the foundation for their vitality as well as their longevity. This is why biblical doctrine is important. This is why it is essential.