Summary: Paul provides instructions to ensure continuation of the Faith from generation to generation.
“Follow the pattern of the sound words that you have heard from me, in the faith and love that are in Christ Jesus.” 
Seminarians are required to study systematic theology. The required courses consist of in-depth studies of the several doctrines that define the Faith of Christ the Lord. On my computer, I have over fifty systematic theologies available to me for my studies, and perhaps as many as three hundred texts presenting various studies of particular theologies. Obviously, I believe that theology is important to understanding the Christian Faith, if not to all who preach the Word, then assuredly to me. I would argue that an understanding of biblical truth is essential for anyone who wishes to teach the Word of God.
However, no one should think that the Bible is a textbook of systematic theology. Similarly, though Paul was a doctrinal preacher, he did not leave us a systematic theology as such. Writing Timothy, the Apostle to the Gentiles wrote in expansive terms; and many of his letters that we have received likewise reveal that he painted with a broad brush. This does not mean that we are left to wonder what is true and what is errant; it does mean that we are responsible to consider the entirety of his writing to understand the truths he revealed.
Neither Paul nor any of the men who gave us the Scriptures wrote out of the bounty of their imagination. As Peter states in the second letter drafted to the believers in the Diaspora, “We did not follow cleverly devised myths when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty. For when he received honor and glory from God the Father, and the voice was borne to him by the Majestic Glory, “This is my beloved Son, with whom I am well pleased,” we ourselves heard this very voice borne from heaven, for we were with him on the holy mountain. And we have the prophetic word more fully confirmed, to which you will do well to pay attention as to a lamp shining in a dark place, until the day dawns and the morning star rises in your hearts, knowing this first of all, that no prophecy of Scripture comes from someone’s own interpretation. For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit” [2 PETER 1:16-21].
The affirmation concerning the origin of Scripture seems to me somewhat dry, even pedestrian. Many contemporary translations have sought to capture the fire spilling out as Peter wrote. I refer to one example of the pertinent verses from a recent translation. “When we apostles told you about the powerful coming of our Lord Jesus Christ, we didn’t base our message on clever myths that we made up. Rather, we witnessed his majesty with our own eyes… First, you must understand this: No prophecy in Scripture is a matter of one’s own interpretation. No prophecy ever originated from humans. Instead, it was given by the Holy Spirit as humans spoke under God’s direction” [2 PETER 1:16, 20, 21 GOD’S WORD].  Scripture was not invented out of the fertile imaginations of mere men. The testimony of those who wrote was that the Spirit of God directed them to put His words into written form. The Spirit of God superintended those who wrote Scripture so that we have precisely what He meant us to have.