The most serious objection to systematic teaching, based on the laws of teaching, has sometimes come from [Christian leaders] and others, who have assumed that the principal aim of [Bible study] is to impress rather than to instruct; and that skillful teaching, if desirable at all, is much less important than warm appeals to the feelings and earnest exhortations on the proper occasions. But what exhortation will have such permanent power as that which is heralded by some clear truth? If the choice must be between the warmhearted teacher who makes gushing appeals, and the coldhearted one who stifles all feeling by his indifference, the former is perhaps to be preferred; but why either? Is there no healthful mean between steam and ice for the water of life? The teacher whose own mind glows with the truth, and who skilfully leads his pupils to a clear understanding of the same truth, will not fail in inspirational power.
-John Milton Gregory, The Seven Laws of Teaching [first published in 1884(!)]