What role does a teacher play?

In the Hebrews study, Pastor Armstrong stated that Paul in his letters would not have cited the spiritual gift of teacher if we didn't need one. But then what about John's words: As for you, the anointing which you received from Him abides in you, and you have no need for anyone to teach you; but as His anointing teaches you about all things, and is true and is not a lie, and just as it has taught you, you abide in Him. (1 John 2:27) How can I reconcile these verses?

As Paul says:

Eph. 4:11 And He gave some as apostles, and some as prophets, and some as evangelists, and some as pastors and teachers,
Eph. 4:12 for the equipping of the saints for the work of service, to the building up of the body of Christ;
Eph. 4:13 until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ.
Eph. 4:14 As a result, we are no longer to be children, tossed here and there by waves and carried about by every wind of doctrine, by the trickery of men, by craftiness in deceitful scheming;
Eph. 4:15 but speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ,
Eph. 4:16 from whom the whole body, being fitted and held together by what every joint supplies, according to the proper working of each individual part, causes the growth of the body for the building up of itself in love.

Paul says that saints grow spiritually as a result of an equipping process, and the Lord provides for that equipping by giving the body certain spiritual gifts like the gift of teaching. Therefore, believers must seek out those in the body with the gift of teaching so we may take advantage of what God is accomplishing through their service, and in that way we may achieve our greatest spiritual growth. Without the service of those who are gifted to teach, we would be less than fully equipped, Paul says, which is why such individuals are present in the body.

At the same time, all believers have access to the Spirit of God so that they may learn all things, the Bible says. These two truths work together in God’s economy. The Spirit of God grants the gift of teaching to some in order that they may help us understand the truth of Scripture, while at the same time the Spirit speaks to us individually confirming (or denying) what we hear from our teachers. The fact that the Spirit lives in each of us doesn’t deny the truth that God grants some members of the body greater understanding of the Bible and a special ability to communicate it to us.

For example, you are learning the Bible through the teaching of Pastor Armstrong. Pastor Armstrong is spiritually gifted to teach, and you are receiving the benefit of that gift. At the same time, the true Teacher is the Holy Spirit, Who has given Pastor Armstrong the knowledge he shares in his teaching and has spoken to your heart confirming what you hear.