Summary: Not everyone who claims to be a teacher has received appointment from God.
“Certain persons, by swerving from these, have wandered away into vain discussion, desiring to be teachers of the law, without understanding either what they are saying or the things about which they make confident assertions.” 
Ultimately, it is not the one who is the most polished speaker who changes lives; it is the one who knows the subject matter to be addressed and who is best able to communicate truth who will transform the lives of those who listen. Jeremiah, confronting false prophets, spoke on behalf of the LORD,
“Who among them has stood in the council of the LORD
to see and to hear his word,
or who has paid attention to his word and listened?
Behold, the storm of the LORD!
Wrath has gone forth,
a whirling tempest;
it will burst upon the head of the wicked.
The anger of the LORD will not turn back
until he has executed and accomplished
the intents of his heart.
In the latter days you will understand it clearly.
“I did not send the prophets,
yet they ran;
I did not speak to them,
yet they prophesied.
But if they had stood in my council,
then they would have proclaimed my words to my people,
and they would have turned them from their evil way,
and from the evil of their deeds.”
Today, multiplied preachers fill the pulpits of the nation, numerous personalities present their thoughts via radio, television and print media; nevertheless, those who speak the truth and who have something worth hearing may be in a decided minority. Those who speak as impelled by the Spirit of God may be rarer still. Self-help books instructing the unwary how to have a successful life and which are written by gurus of self-fulfilment fill the shelves of numerous bookstores; and television personalities promote every conceivable form of self-analysis and quick fixes for multiplied deficits—real or imagined. Despite all this “help,” people continue to be decidedly unhappy with their situation in life.
Those who occupy the sacred desk, labouring to produce love—love that arises “from a pure heart and a good conscience and a sincere faith,” are increasingly rare. Though the schools producing preachers may be faulted, I suggest that congregations bear awesome responsibility for the present situation because they refuse to hold preachers accountable to the Word.
I suppose a case can be made for accusing the preachers themselves for this present crisis. After all, we preachers have too often failed in our fiduciary duties to declare the whole counsel of God. Nevertheless, the professed people of God must assume responsibility to know the Word, whether the preacher declares the Word of not. Moreover, those who name the Name of the Lord Christ must apply the Word both in their daily lives and in the life of the congregation. I contend that those who occupy the pews must act with discretion and humility before the Lord, but they must accept responsibility to know and to do the will of God.
SWERVING FROM LOVE — Multiple passages in the Word inform us that those appointed to eldership are required to be teachers. As one example, Paul writes, “An overseer must be above reproach, the husband of one wife, sober-minded, self-controlled, respectable, hospitable”; take special note of the next qualification, “able to teach” [1 TIMOTHY 3:2]. Paul will iterate this necessity in his second letter to Timothy, when he writes: “You then, my child, be strengthened by the grace that is in Christ Jesus, and what you have heard from me in the presence of many witnesses entrust to faithful men who will be able to teach others also” [2 TIMOTHY 2:1, 2].