And if knowledge, obtained by human means, is not to be despised, then it will follow that the means of obtaining it are not to be neglected, viz. study; and that this is of great use in order to a preparation for publicly instructing others.  And though having the heart full of powerful influences of the Spirit of God, may at some time enable persons to speak profitably, yea, very excellently, without study; yet this will not warrant us needlessly to cast ourselves down from the pinnacle of the temple, depending upon it that the angel of the Lord will bear us up, and keep us from dashing our foot against a stone, when there is another way to go down, though it not be so quick.  And I would pray, that method, in public discourses, which tends greatly to help both the understanding and memory, may not be wholly neglected.

-Jonathan Edwards-

Distinguishing Marks of a Work of the Spirit of God