What is the very basis of good teaching?
Repetition is the very basis of good teaching. The Holy Spirit, as the Master Teacher, knows better than any secular teacher that repeating truth over and over is what drives it home. Scripture itself demonstrates this by repeating its themes again and again, and that pattern is deliberate, not accidental.
Les explains that the repetition running through these lessons is not merely his own habit, because the Scripture is repetitious too. He points out how many times the Bible will repeat and repeat and repeat, and he ties that pattern directly to the Holy Spirit, calling Him the Master Teacher. The Holy Spirit knows better than any secular teacher that repetition is the very basis of good teaching. So when the same themes come around again in a Bible study, that is by design, following the method the Spirit Himself uses to press truth into the listener. Les also mentions that in an upcoming program he may go back and put his timeline on the board again, since many people wrote or called to say the timeline was what first got them interested in the program and in Bible study, and it has been a long time since it was displayed.