For this post let's continue to answer the question, "Why is the study of doctrine important anyway?" In previous posts I have given the first two reasons. Here is the third reason.
The third reason that studying doctrine is advantageous is due to the fact that the understanding of doctrinal truth leads (in part) to our salvation, and the understanding of doctrinal truth is the primary instrument of our sanctification. Christianity is not mystical, but logical. Nobody, who is reading this blog post and has come to a genuine saving knowledge of Jesus Christ was "saved" apart from the hearing of doctrinal information. The reason is simple- the Gospel is doctrine! The truths of forgiveness, eternal life, substitution, justification, etc. are......well...doctrines!
Two key passages show us that it is the message of the Gospel spoken and understood first by the mind (through the power of the Holy Spirit) that results in salvation. The first one is Romans 10:17 which says, "So faith comes from hearing, and hearing by the word of Christ". The message about Christ- His saving work for elect sinners- is the Gospel. And the hearing of this (or, to be fair, the reading of it as well) is what saves. God has chosen to engage the mind first in order for salvation to take place. This is not denying the work of regeneration that the Spirit ministers. Rather it is affirming it. I am simply saying that the Spirit "does the work" when someone (anyone) is saved. But the instrument that He uses is the doctrine of the Gospel. The tool he uses is the Gospel.
There is a nice size garden behind my house. It is not mine, but my neighbor's. My neighbor is extremely "handy". He works outside often and knows how to do a lot that I have no clue about. I guarantee you that his garden successfully produces vegetables for a number of reasons. The weather, soil, etc. all play a role in my neighbor's success at gardening. However, having proper gardening tools, and purchasing and planting good seed is very important as well. In fact, I would submit to you that if he had no gardening tools whatsoever, he would not be that successful at growing vegetables. That is nothing against him, but the simple fact is that the success of a garden depends largely upon certain tools. My neighbor does the work itself, but he uses certain instruments to bear a good crop. Now the Spirit works the same way. The Spirit does the work of salvation on a heart, but the instrument He uses is the doctrine of the Gospel. There is no other tool. That is a simple fact.
I promised you two verses to prove this point. Here is the other verse, "For since in the wisdom of God the world through wisdom did not come to know God, God was well-pleased through the foolishness of the message preached to save those who believe" (I Cor. 1:21). The same thought as that of Rom. 10:17 is being expressed here as well. The means (instrument) that God has chosen to save people is the doctrine of the Gospel.
My overall point is that we ought to have a propensity to love doctrine (and the study of it) because it is doctrine which led to our salvation. That is simple enough, I think. But look at the second half of my statement given above..."and the understanding of doctrinal truth is the primary instrument of our sanctification." In other words, doctrine led to our salvation, but it also leads to our sanctification as the Spirit of God is pleased to apply doctrine to our lives for the purpose of godliness.
To prove this point we need look no further than Christ's prayer for His elect in John 17. I will not take the time to explain this passage in detail. However, note especially vss. 18-21. In effect, Christ is praying that all believers be sanctified in truth. Vs. 17 says, "Your Word is truth". The word concerning what? Its simple, right? Christ is speaking about the word concerning the Gospel and all the rich truths that flow from it which are found in Scripture. In other words, it is the study, learning, and understanding of this truth (found in Scripture) that sanctifies us (sets us apart progressively for God's holy purposes to the glory of Jesus Christ). John MacArthur puts it this way, “…believers are set apart for God and His purposes alone so that the believer does only what God wants and hates all that God hates…Sanctification is accomplished by means of the truth, which is the revelation that the Son gave regarding all that the Father commanded Him to communicate and is now contained in the Scriptures left by the Apostles”.
We should study doctrine, as believers, because it is the means by which we grow spiritually, and it was the means that paved the way for spiritual growth to even become a category in our lives because it was what the Spirit of God used to give us new life.
-Pastor Andy