It is often said that doctrine is not worth talking about. Much damage has been done in the name of doctrine. One can point to Nazi Germany or Apartheid. Doctrine just divides, so what’s the use? Shouldn’t we just focus on the Kingdom and do what Jesus would do in this world?
Deeds before creeds is the modern mantra in so-called Christian circles. However common it is the proposal is very wrong. The Bible is not about what to do as much as it is what to believe. The Bible calls us to see and savor Jesus, to know Him and be so transformed by the truth of the Bible that gospel fruit is produced and God is glorified by obedience. When the Christian life becomes about knowing Christ and Him crucified, the need for sound doctrine is heightened. After all, do we have to continue to worship a God fashioned in the furnace of our fallen minds? Or would we rather worship God as He has revealed Himself? Since God has set us free from our blindness we are indeed free to stop making God in our own image. We become what we worship and we worship that which we know.
Unprofitable and Worthless
Paul tells us what is unprofitable and worthless in Titus 3. There is doctrine that is unprofitable. Doctrine in an of itself is of no avail to anyone. You see, everyone is a theologian. Everyone has a running systematic theology. Everybody, even the non-believer has doctrine. I love systematic theology. But I am reminded that the practice is not an end in itself and is much less a sure fire sign of biblical fidelity. For all the good of Reformed/Evangelical Systematic theology, there are really bad systematics coming from other traditions. Charles Finney wrote a systematic theology, after all (in which he denied original sin).
Paul lists these doctrines that are not helpful: foolish controversies, genealogies, dissensions and quarrels about the law. It is these things that the false teachers Titus was dealing with liked to harp on. How often do people who live unholy lives major in the minors? It is poor doctrine to take what is meaningless and make it front and center. We know from the rest of Paul’s letter that the false doctrine of these men had led to licentious living. Paul sees the lack of holiness of these men and deems their doctrine unholy. Perhaps, better put, Paul knows their doctrine is worthless and so it will only produce worthlessness.
What makes doctrine profitable? We must be quite careful to not become theological pragmatists. A doctrine’s worth is not determined by what it produces. Doctrinal worth is found in its truthfulness. God has determined what is sound and has given us the Bible to know what that it. Sound (healthy) doctrine is that which gives us God, to know Him and glorify Him in our enjoying of Him.
Like all things, doctrine is for Christ, by Christ and to Christ. Theology is for doxology. The center of Christian doctrine is the gospel. It is the gospel that produces good works. A heart transformed by the gospel will produce good fruit. Once God makes us good trees, good fruit naturally flows. Titus says the following:
 But when the goodness and loving kindness of God our Savior appeared,  he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit,  whom he poured out on us richly through Jesus Christ our Savior,  so that being justified by his grace we might become heirs according to the hope of eternal life.  The saying is trustworthy, and I want you to insist on these things, so that those who have believed in God may be careful to devote themselves to good works. These things are excellent and profitable for people. (Titus 3:4-8 ESV)
Paul basis his conversation on ethics in the gospel. Christians should live moral lives, but moral lives out of a heart that has been justified by the obedience of Christ. It profits no one to stare at the fruit (though there is a time for introspection). But most growth comes by looking outside of ourselves to Christ. Paul discusses regeneration, justification, glorification and adoption. It is these things that Paul says are profitable. They are profitable first and foremost because they help us know God. The gospel is for our joy in God. That joy in God produces holiness. A heart satisfied with God finds less and less appetite for sin. In the light of His glory and grace the things of this world grow strangely dim. There is a correlation between our knowledge of God and our walking in holiness before God, not to be justified but because we have been justified.
Doctrine matters. It matters for the glory of God. What God has said is important. But sound doctrine is practical. It is harded to hold grudges when we see how God should have kept His wrath over us. It is harder to be proud when we see the foolishness of our efforts before His holiness. Doctrine is for life. Doctrine is for a holy life, a life that is happy in Christ.