"But refuse foolish and ignorant speculations, knowing that they produce quarrels. The Lord's bond-servant must not be quarrelsome, but be kind to all, able to teach, patient when wronged, with gentleness correcting those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth, and they may come to their senses and escape from the snare of the devil, having been held captive by him to do his will." (2 Timothy 2:23-26)There is something very seductive to a teacher about showing the depths of his or her understanding in expounding upon deep and hidden mysteries of the scriptures known only to a few truly enlightened individuals. We love to have something new to share; to wow the crowds with our intellectual insight and understanding. Especially where the word of God is unclear, we like to shine with our own personal speculations surrounding it; expounding on our own personal interpretation of the uncertainties to the pleasure of others. This is a temptation that all servants of God, and teachers especially, which we must firmly avoid.
There may be a lot in the word of God that seems uncertain to us, and a lot we don't understand, but the majority of the scriptures are direct and easy enough for anyone to understand and follow. It doesn't take a seminary degree to read and understand the message of God expressed through His word. In fact, it was often the religious elite, who claimed understanding into the scriptures, who were the first to reject Jesus, and it was the lowly and simple who received Him gladly. The religious leaders remarked that Jesus' disciples, "were uneducated." (Acts 4:13) Meaning literately to be "with out letters," such as BS, MS, or Ph.D. Simple uneducated men were able to understand and teach the message of God then and so it is still today.
When we are given to our own speculation, insight, and interpretations, we are easily drawn into quarrels with other people of differing opinions. I have know people who, while loving the Lord, loved the quarrel even more. They delight in nothing more than arguing with others. They delight in the challenge of proving themselves right. Every new encounter, each new person the meet, is another opportunity for victory in discourse and opinion. Such people can't talk about anything else other than their favorite doctrine or how you or someone else you know is wrong and they themselves are right. In proving themselves right, it matters little to them if they must first assault and tear down your own faith; your acquiescence to their position is all that matters.
The goal of teaching is not to be right. Rather, Paul tells us that, "the goal of our instruction is love from a pure heart and a good conscience and a sincere faith." (1 Timothy 1:5) The goal of our instruction should be the benefit of our hearers. We should teach, not for our own aggrandizement, but for the useful profit of those who choose to listen. People do not need our "deep insight." They do not need to understand the "hidden mysteries" of the scriptures. Rather, they need to know, understand, and obey what the scriptures plainly speak to us and to the world around us. Paul wrote that, "we write nothing else to you than what you read and understand." (2 Corinthians 1:13) Simple truths that are easy to understand and apply to our lives. Peter wrote, "I will always be ready to remind you of these things, even though you already know them." (2 Peter 1:12) No new "truth" or revelation but just a reminder of what we already know; to bring it to our remembrance and to exhort us to its obedience. This is the true character and nature of a teacher in God's household.