Physical diseases have symptoms, or marks, by which they may be diagnosed. In fact, that is how we become aware that we are sick: We identify something unusual about our health. We recognize the telltale signs that something is wrong.

The same is true of false teaching. Those infected by it will manifest certain characteristics. In Ephesus, where Timothy was pastor, there were already some who were carriers of the disease of false doctrine (1 Timothy 1:3–4, 6–7, 20; 4:1–5). In response, Paul didn’t call out only some of them; he gave a broad warning concerning anyone who had departed from sound doctrine. This would prepare Timothy for the varieties of false teaching the church would encounter.

If anyone advocates a different doctrine and does not agree with sound words, those of our Lord Jesus Christ, and with the doctrine conforming to godliness, he is conceited and understands nothing; but he has a morbid interest in controversial questions and disputes about words, out of which arise envy, strife, abusive language, evil suspicions, and constant friction between men of depraved mind and deprived of the truth, who suppose that godliness is a means of gain. (1 Timothy 6:3–5)

In his warning, Paul highlights two marks of these wolves: what they affirmed and what they denied. These two characteristics stand as tests of a person’s doctrine—and more than that, of their overall spiritual health.  

The False Teacher's Affirmation

First, a false teacher advocates a different doctrine. The phrase “advocates a different doctrine” comes from the Greek word heterodidaskaleō, a compound word from heteros (“other”) and didaskō (“to teach”). It describes any teaching that contradicts God’s revelation in Scripture. Such teaching is at best heterodoxy (rather than orthodoxy). At worst, it is heresy.

False teaching may take many forms. It may deny God’s existence or teach error about His nature and attributes. It may deny or reinvent the Trinity. Error about Christ’s person and work is also common in false systems—those who deny His deity, eternality, virgin birth, sinless perfection, substitutionary death, bodily resurrection or future return show signs of a deadly infection. False teachers also teach error about the nature, person, and works of the Holy Spirit. Yet another strain of the disease of false teaching denies the authenticity, inspiration, authority, or inerrancy of Scripture. Many of these strains are virulent in the church today.

To spot the carriers of spiritual disease, believers must be well grounded in Scripture and sound doctrine. Those who know the Word and understand what it teaches will easily spot teaching contrary to it. They will be spiritual young men, who have overcome the evil one because they are strong in the knowledge of God’s Word (1 John 2:14). Since the evil one primarily operates in false systems of religion, this indicates a level of maturity where sound doctrine has been laid as a solid foundation. Spiritual young men, by knowing the Word which abides in them, overcome the lies of Satan. Those who have grown past being spiritual infants through their knowledge of sound doctrine can see error for what it is.

In his farewell address to the Ephesian elders, Paul reminded them of their responsibility to diagnose and deal with error:

I did not shrink from declaring to you the whole purpose of God. Be on guard for yourselves and for all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood. I know that after my departure savage wolves will come in among you, not sparing the flock; and from among your own selves men will arise, speaking perverse things, to draw away the disciples after them. Therefore be on the alert, remembering that night and day for a period of three years I did not cease to admonish each one with tears. And now I commend you to God and to the word of His grace, which is able to build you up and to give you the inheritance among all those who are sanctified. (Acts 20:27–32)

After warning them of the threat of false teachers, Paul pointed out the only antidote, the “word of His grace” (v. 32). According to Ephesians 6:17, the Christian’s offensive weapon against false teaching is the “the sword of the Spirit, which is the word of God.” Paul defines a true spiritual leader as one “nourished on the words of the faith and . . . sound doctrine” (1 Timothy 4:6; cf. v. 16; 2 Timothy 1:13–14; 2:2). The primary function of a spiritual leader is to feed his people the Word. They will then avoid the poison of false doctrine and grow to maturity (cf. Ephesians 4:11–15).

The False Teacher's Denial

Another mark of false teachers is what they deny. Their teaching not only affirms error, but also disagrees with “sound words, those of our Lord Jesus Christ” (1 Timothy 6:3). False teachers are not in agreement with spiritually wholesome and beneficial words. That believers need to pay attention to sound, healthy teaching is repeatedly emphasized in the pastoral epistles (cf. 1 Timothy 1:10; 2 Timothy 1:13; Titus 1:9; 2:1).

Paul further describes “sound words” as “those of our Lord Jesus Christ.” That phrase refers to more than the quotes of our Lord given in the gospels. It encompasses His message as revealed in Scripture, “the word of Christ” (Colossians 3:16; cf. 1 Thessalonians 1:8; 2 Thessalonians 3:1). It is that Word that provides the healthy teaching by which believers grow. Peter wrote, “Like newborn babies, long for the pure milk of the word, so that by it you may grow in respect to salvation” (1 Peter 2:2).

False teachers may claim to be committed to Scripture, but they do not maintain what it truly teaches. They may speak of Jesus and the Father, but the heart of their ministry will not be the Word of God. They will either add to it, take away from it, interpret it in some heretical fashion, add other “revelations” to it, or deny it altogether.

False teachers also deny “the doctrine conforming to godliness” (1 Timothy 6:3). A key test of any teaching is whether it produces godliness when truly embraced. Unscriptural teaching will result in an unholy life. “Godliness” (Gk., eusebeia) refers to “piety,” “reverence,” or “likeness to God.” Such behavior is the fruit of truth. In Matthew 7:15–20, Jesus warned,

Beware of the false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves. You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they? So every good tree bears good fruit, but the bad tree bears bad fruit. A good tree cannot produce bad fruit, nor can a bad tree produce good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. So then, you will know them by their fruits.

Heresy has no power to produce genuine godliness. When you examine those today who deride doctrine, you discover they are also like those in the last days who Paul says “will be lovers of self, lovers of money, boastful, arrogant, revilers, disobedient to parents, ungrateful, unholy, unloving, irreconcilable, malicious gossips, without self-control, brutal, haters of good, treacherous, reckless, conceited, lovers of pleasure rather than lovers of God, holding to a form of godliness, although they have denied its power . . . . [They are] always learning and never able to come to the knowledge of the truth” (2 Timothy 3:2–5, 7). Sound doctrine leads to holy living, and its absence to unholy living.

That is one reason why discerning false doctrine is not a matter of interest or preference. It isn’t an optional extra for those who are uptight or overly scrupulous. It is a matter of the spiritual health of the church.

The church must identify and eliminate error if we are to please our Lord.

(Adapted from The MacArthur New Testament Commentary: 1 Timothy)