There are two nouns that have been translated “teaching” or, more traditionally, “doctrine”, in the New Testament. Didache, used 29 times, appears usually to be used of the act of teaching, and didaskalia, used 19 times, of the content of what is taught, although these are not clearly divided categories. If any of you can come up with a better distinction, I will gladly add it to this post.
More important than that, however, is the realization that neither word bears any resemblance whatever to the neatly sorted and proof-texted lists of theological propositions commonly promoted as “doctrines”, to which individuals are required to subscribe in order to be considered acceptably “orthodox.” (Remember James’ statement (see w.s. #1) that the devil himself could readily subscribe to those lists of “beliefs.”) In 17th century England (Shakespeare and King James were contemporaries), the word “doctrine” simply meant “teaching.” In early American history, it referred to a political pronouncement (“the Monroe Doctrine”).
When Jesus warned his followers to “beware of the didache (teaching, doctrine) of the scribes and Pharisees” (Mt.16:12), it was their behavior that he had been challenging. More frequently, he critiqued their “teaching (didaskontes) as “doctrines” (didaskalias) the commandments of people” (Mt.15:9, Mk.7:7), which sounds suspiciously like the folks today who harangue their hearers about their carefully contrived and footnoted “statements of doctrine.” This may seem to you like a tired refrain, but I will ask you once again, What did JESUS say?” And if you can find any instance of the Lord Jesus arguing any kind of systematic theology, please let me know.
Jesus’ teaching [doctrine] that amazed his hearers was his ability (Mk.1:27 and Lk.4:32) to command the departure of unclean spirits, (Mk.11:18) to drive the opportunistic merchants out of the temple, and (Mt.22:33) to make the scholarly scribes and Pharisees look silly!
Jesus advocated one single test of “orthodoxy”: (Jn.7:16, 17) “My teaching is not mine, but (has its source in) the one who sent me. If anyone wants to do his will, he will know about the teaching [doctrine], whether it comes from God.” Folks, it’s all about following instructions!
When Peter and John were arrested for “teaching in the Name (see W.S. #24) of Jesus” (Ac.3 and 4), they replied simply, (4:19) “If it is just [right] before God to listen to you rather than God, you must judge!” and proceeded to continue to teach as before (5:28-29) the message of Jesus’ resurrection, as evidence of his vindication and supremacy! In Athens, Paul’s “preaching about Jesus and the resurrection” (Ac.17:18-19) precipitated the Areopagus discussion about “what new thing this teaching [doctrine] is”. As noted in W.S. #35, Jesus’ resurrection is the central theme of the whole New Testament: both the definitive proof of his identity, and his credential as the rightful Sovereign of his Kingdom!
Remember that the “teaching assignment” given to his followers in Mt.28:20 was quite specific: those to whom the news of the Kingdom is carried, are to be taught to follow the King’s instructions!
Paul praised the group at Rome (6:17) for turning from the futility of their former lives, to a life of “obedience to the example of the teaching” (didache) they had received. He reminded those at Colossae “Since you were resurrected with Christ (3:1),” get about the business of incorporating that fact into your lives. Timothy and Titus both received very explicit instructions for teaching – and modeling – faithful living.
As was the case with prophecy (W.S.#45), there is also false teaching that must be discerned and corrected. It may involve (Rom.6:17) those who cause divisions in the brotherhood, (Gal) those who try to reinstitute Jewish legal requirements, or (Col.2:22) similar ascetic practices from pagan traditions. There is a rather explicit list in I Tim.1:3-11, along with the reminder (which has never gone out of date), “The goal of the commandment is love from a clean heart and a good understanding, and faithfulness without pretense (1:5)”. The warning is repeated in 4:1-4. In fact, the whole letter (I Tim) could be considered a “teacher’s manual.” Clearly, again, it is Jesus’ words that are to be taught. Subjects specifically labeled in the Gospels as “his teaching and doctrine” include his parables, the Sermon on the Mount, his warnings about the scribes and Pharisees, and his relationship with the Father.
Unlike prophecy, which, as we have seen (W.S. #45), entails a direct message from God, usually bearing upon a specific situation, faithful teaching does draw upon the knowledge, experience, and study of the teacher. II Tim.2:15 succinctly expresses the goal: “correctly handling the message of the truth.” The Scripture is the primary source – and it should be incumbent upon anyone who presumes to teach, to learn to understand it accurately – for it is indeed “useful for teaching, for reproving, for correction, and for education in justice, in order that God’s person may be mature, prepared for every good effort.” (I Tim.3:16-17). And remember that , unlike “moderns” who claim that “scripture” in the first century referred only to the Old Testament, our brother Peter begs to differ, (II Pet.3:16), including both “brother Paul” and other writers in that designation. There were many “writings”(the literal meaning of graphe or grammata,) circulating in the first century church, which required as much evaluation and discernment as the prophecy and teaching. (Note that Paul referred to letters incorrectly attributed to him – II Thes.2:2.)
It is also prudent to bear in mind James’ warning that “we who teach will receive stricter judgment.”(3:1).
Nevertheless, when our risen Lord ascended “higher than all the heavens”, he gave “apostles, prophets, evangelists, shepherds, and teachers” to his church: “for the purpose of equipping God’s people to do work of service [ministry], and to build up the Body of Christ, until we all arrive into the unity of faithfulness,and of intimate acquaintance with the Son of God: that is, into mature adulthood – into a measure of the maturity whose source is the fulness [completeness] of Christ. (The purpose is ) that we be no longer babies, agitated and carried around by every wind of teaching [doctrine], deceitfully manipulated by people who are deliberately trying to mislead us, but as we interact truthfully, in love, we may grow up in every way into him who is the Head – Christ. From him, the whole Body, joined together [harmonized] and knit together, through the proper functioning of every available ligament , according to the measured working of each individual part, makes bodily growth for building itself up in love.” (Eph.4:12-16)
That’s everybody’s job, folks! Let’s get busy!
The Pioneers' New Testament 
There were many “writings”… circulating in the first century church, which required as much evaluation and discernment as the prophecy and teaching.
Interesting counterpoint to the usual use of Peter’s reference to Paul’s letters as “writings” and the usual prooftexting of 2 Tim 3:16. This further buttresses the notion I’ve been arguing for a while now, that discerning from within the content of the writings (Scripture) is part of the duty of the community of faith.