W. Austin Gardner
Mentoring—A Forgotten Art

In the days when the church was just getting started and the New Testament was being written, boys were groomed into men through the relationships they had with older men. Call it mentoring, apprenticing, tutoring, whatever—the lessons of life were learned through life-on-life relationships. In fact, this seems to be the pattern for personal development throughout Scripture (see Mentoring Relationships in the Bible, pp. 180–181).
These mentoring relationships were carried on not only by people of faith, but by society in general. The method continued until about a hundred years ago, when the Industrial Revolution and other factors brought about a radical change in the way knowledge and skills are taught.
Nowadays, teaching means telling, and testing boils down to the student cramming as much information as possible into his head, and then regurgitating it onto a piece of paper during an exam.
Howard Hendricks and William Hendricks, As Iron Sharpens Iron: Building Character in a Mentoring Relationship (Chicago, IL: Moody Publishers, 2009).