“Preach the word!” (2 Timothy 4:2, NKJV).

To the church today, those words may sound unusual as a pastor’s primary job description. We are used to all kinds of other “ministry” endeavors fighting for position in a long list of pastoral responsibilities.

Even for those who affirm the primacy of preaching, the kind of preaching they want is purely practical—thus, doctrine (which is presumed to be utterly impractical) is the mortal enemy. If a sermon doesn’t have an immediate, obvious application to every listener, then it is viewed as a waste of time.

But that is not Christ’s expectation for His church, and especially for those who lead it. Paul’s pastoral epistles demonstrate this.  

The Charge to Teach Doctrine

In his letters to Timothy and Titus, Paul teaches that the sacred responsibility of the man of God is to live, proclaim, and guard the truth. In fact, 1 Timothy begins that way: “As I urged you when I was going to Macedonia, remain at Ephesus so that you may charge certain persons not to teach any different doctrine” (1 Timothy 1:3, ESV).

There must be no other teaching. Timothy was to stop the spread of false doctrine by holding the line against encroaching error.

The issue comes up again in 1 Timothy 4:1, “But the Spirit explicitly says that in later times some will fall away from the faith, paying attention to deceitful spirits and doctrines of demons.” People will depart from the truth because they are led astray by seducing spirits through hypocrites who speak lies (v. 2).

In contrast, Timothy was to be “a good servant of Christ Jesus, constantly nourished on the words of the faith and of the sound doctrine” (v. 6). He was to “prescribe and teach these things” (v. 11), “give attention to the public reading of Scripture, to exhortation and teaching” (v. 13), and “pay close attention to yourself and to your teaching; persevere in these things” (v. 16). Clearly, the protection and propagation of doctrine was the task with which Paul—and ultimately, God—had charged Timothy.

In 1 Timothy 5:17, Paul reinforces this call for pastors in general: “The elders who rule well are to be considered worthy of double honor, especially those who work hard at preaching and teaching.” The utmost call of the elder is to work hard at preaching and teaching. He must know and defend sound doctrine.

Paul directs similar orders to Timothy in chapter 6: “Teach and preach these principles. 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” (vv. 2–4). There is a standard of sound words—that is, doctrine—which aligns with the words of Christ. It is the pastor’s role to teach those words. As a pastor, Timothy was to “fight the good fight” for the faith, defending and upholding God’s truth until the Second Coming (1 Timothy 6:12–14).

Paul finishes the letter on this note with an emphatic appeal, “O Timothy, guard what has been entrusted to you, avoiding worldly and empty chatter and the opposing arguments of what is falsely called ‘knowledge’—which some have professed and thus gone astray from the faith” (vv. 20–21). If Timothy didn’t contend for the faith, his ministry would be in vain.

Paul didn’t stop there. He revisits this crucial issue in his second epistle to Timothy. In the first chapter Paul restates his closing remarks from his first letter: “Retain the standard of sound words which you have heard from me, in the faith and love which are in Christ Jesus. Guard, through the Holy Spirit who dwells in us, the treasure which has been entrusted to you” (2 Timothy 1:13–14). Retain and guard Christian doctrine—that is the charge to every pastor. That is why Paul compares Timothy to a soldier in the next chapter (2 Timothy 2:3). The pastor, in a preeminent way, is involved in a battle for the truth—and he must fight.

In chapter 2, Paul continues to instruct Timothy about preaching the Word. He writes, “Be diligent to present yourself approved to God as a workman who does not need to be ashamed, accurately handling the word of truth” (v. 15). He was to “cut it straight,” ensuring that the truth he preached was the meaning of the biblical text.

Then in 2 Timothy 3:13, Paul wrote, “But evil men and impostors will proceed from bad to worse, deceiving and being deceived.” Timothy, on the other hand, was to “continue in the things you have learned and become convinced of” (v. 14), specifically what he had been taught from Scripture (2 Timothy 3:15), which is “inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness; so that the man of God may be adequate, equipped for every good work” (vv. 16–17).

That leads into the most serious command of the pastoral epistles:

I solemnly charge you in the presence of God and of Christ Jesus, who is to judge the living and the dead, and by His appearing and His kingdom: preach the word; be ready in season and out of season; reprove, rebuke, exhort, with great patience and instruction. For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to their own desires, and will turn away their ears from the truth and will turn aside to myths. But you, be sober in all things, endure hardship, do the work of an evangelist, fulfill your ministry. (2 Timothy 4:1–5, emphasis added)

In other words, “Never let go of the truth, Timothy. Even if everyone around you abandons or opposes it, keep the faith.” And Timothy could look to Paul for the example of someone who did just that (2 Timothy 4:7–8).

The Necessity of Theology

The instructions of the pastoral epistles revolve around sound doctrine—the teaching of the Christian faith. Therefore, in order to heed Paul’s commands, pastors must have a grasp of biblical doctrine as a whole, what we often call systematic theology.

Systematic theology simply collects divine revelation in categories, pulls it together, and draws conclusions about what the Bible teaches on a particular subject (such as the doctrine of God, Christ, man, sin, salvation, and so on). It is the doctrine that frames everything a pastor teaches. It puts fences up to keep him within the bounds of Christian orthodoxy. Without systematic theology, pastors are at risk of a multitude of errors in several directions.

That is why a pastor needs to learn systematic theology before he begins preaching. If he knows sound theology, he is restricted from saying something stupid—and won’t resemble a fraud who makes up his aberrant theology on the spot.

If a man began preaching without understanding systematic theology—thinking instead that he had to accumulate it as he went—he would be a very dangerous pastor. He could draw any number of wrong conclusions from a passage without knowing that other passages bring additional clarity to the subject. That is a recipe for misinterpreting and misrepresenting God’s Word.

For example, consider 1 Corinthians 15:22: “As in Adam all die, so also in Christ all will be made alive” (emphasis added). If you were to interpret that passage in isolation, you could well think it teaches universalism. If “all” in the first half of the verse means everyone dies, then would not “all” in the second half mean everyone is saved? No—that’s heresy. And the reason we know that is because the rest of Scripture addresses and clarifies the issue.

Again, that is why pastors need to learn systematic theology before they commence their ministry. We aren’t discovering our theology as if we were the first ones to articulate the truth. We hold to historic, classical theology that has been passed down from the faithful through generations since the New Testament.

When I come to the end of my life, the question won’t be how big my church was or how popular my ministry was. The question will be, “Did he retain and guard the truth?” Paul says to the Corinthians, “It is required of stewards that one be found faithful” (1 Corinthians 4:2, LSB).

The sacred trust of the truth is the issue—so the question of all questions is what a man does with it. Does he teach sound doctrine? Does he defend it? Does he live it? That’s God’s concern for pastors.