Luke 6: He also told them a parable: “Can a blind man lead a blind man? Will they not both fall into a pit?  A disciple is not above his teacher, but everyone when he is fully trained will be like his teacher.
Now here is truly frightening stuff for any teacher who has been teaching for more than just a few years. Those you teach will be like you. The general principle that Jesus is getting at here is that a teacher cannot take people to places he has not been. Teachers must know their stuff. It is not enough to know good teaching techniques and be personable and know how to influence people. If what you are passing on to them is not solid, sixteen-ounces-to-the-pound of biblical doctrine and application, then go do something else. If a blind man takes another blind man by the hand to lead him somewhere they will both get in trouble.
In a culture such as ours where appearance and charisma and popularity are highly valued there will be a greater danger of people being grabbed by the hand by those who cannot see. There is a warning in Jesus’ words here to both teachers of Christian doctrine and life and to their pupils.
Teachers need to read this text and commit themselves afresh to knowing their stuff, living it out in front of those they teach and growing in their own understanding of the truth. Teachers need to ask themselves how happy they would be if all their students turned out like them, because that is what Jesus says is going to happen. This brings to mind Paul’s words to Timothy in I Timothy 4:16.
I Timothy 4: Keep a close watch on yourself and on the teaching. Persist in this, for by so doing you will save both yourself and your hearers.
Do you teach others? Keep a close watch on both the doctrines that you teach and the way that you live. Make sure that you teach only the truth as it is given to us in the Scriptures. And be a person above reproach. Live honestly before the world and before God. It is not only you that you are in danger of ruining. Your students will become like you. Get your act together or get out.
Are you a student of Bible teachers? Maintain a Berean spirit.
Acts 17: The brothers immediately sent Paul and Silas away by night to Berea, and when they arrived they went into the Jewish synagogue.  Now these Jews were more noble than those in Thessalonica; they received the word with all eagerness, examining the Scriptures daily to see if these things were so.
You have a duty to study the Bible on your own. You are not an empty vessel simply waiting to be filled. You are to study and grow as you are taught. You are to be open to the possibility that you may be wrong and that your teacher has turned you in the right direction. You must work at putting the things that you are taught into concrete action in your daily living. Remember that you are not above your teacher. In the teaching relationship your teacher is above you. This is why it is crucial that only sound teachers be appointed in churches.
All of us are teachers and students at the same time. Both positions carry responsibilities. The greater lies with the teacher. You will produce people like yourself. Live so that will not be an embarrassment to you or to the Gospel.