"II. I proceed now to the second thing proposed, viz. to show how this light is immediately given by God, and not obtained by natural means. And here,
"First. 'Tis not intended that the natural faculties are not made use of in it. The natural faculties are the subject of this light: and they are the subject in such a manner, that they are not merely passive, but active in it; the acts and exercises of man's understanding are concerned and made use of in it. God in letting in this light into the soul, deals with man according to his nature, or as a rational creature; and makes use of his human faculties. But yet this light is not the less immediately from God for that; though the faculties are made use of, 'tis as the subject and not as the cause; and that acting of the faculties in it, is not the cause, but is either implied in the thing itself (in the light that is imparted), or is the consequence of it. As the use that we make of our eyes in beholding various objects, when the sun arises, is not the cause of the light that discovers those objects to us.
"Second. 'Tis not intended that outward means have no concern in this affair. As I have observed already, 'tis not in this affair, as it is in inspiration, where new truths are suggested: for here is by this light only given a due apprehension of the same truths that are revealed in the Word of God; and therefore it is not given without the Word. The gospel is made use of in this affair: this light is "the light of the glorious gospel of Christ" (2 Corinthians 4:4). The gospel is as a glass, by which this light is conveyed to us; 1 Corinthians 13:12, "Now we see through a glass…." But,
"Third. When it is said that this light is given immediately by God, and not obtained by natural means, hereby is intended, that 'tis given by God without making use of any means that operate by their own power, or a natural force. God makes use of means; but 'tis not as mediate causes to produce this effect. There are not truly any second causes of it; but it is produced by God immediately. The Word of God is no proper cause of this effect: it don't operate by any natural force in it. The Word of God is only made use of to convey to the mind the subject matter of this saving instruction: and this indeed it doth convey to us by natural force or influence. It conveys to our minds these and those doctrines; it is the cause of the notion of them in our heads, but not of the sense of the divine excellency of them in our hearts. Indeed a person can't have spiritual light without the Word. But that don't argue, that the Word properly causes that light. The mind can't see the excellency of any doctrine, unless that doctrine be first in the mind; but the seeing the excellency of the doctrine may be immediately from the Spirit of God; though the conveying of the doctrine or proposition itself may be by the Word. So that the notions that are the subject matter of this light, are conveyed to the mind by the Word of God; but that due sense of the heart, wherein this light formally consists, is immediately by the Spirit of God. As for instance, that notion that there is a Christ, and that Christ is holy and gracious, is conveyed to the mind by the Word of God: but the sense of the excellency of Christ by reason of that holiness and grace, is nevertheless immediately the work of the Holy Spirit."
Jonathan Edwards, "A divine and supernatural light" (August 1733), Doctrine II. The works of Jonathan Edwards, ed. Perry Miller et al., vol. 17 (Sermons and discourses, 1730-1733, ed. Mark R. Valeri (New Haven: Yale University Press, 1999)), p. 416-17.