God made man in His own image and placed within him an organ by means of which he could know spiritual things. When man sinned, that organ died. “Dead in sin” is a description not of the body nor yet of the intellect, but of the organ of God-knowledge within the human soul. Now men are forced to depend upon another and inferior organ and one furthermore that is wholly inadequate to the purpose. I mean, of course, the mind as the seat of his powers of reason and understanding.
Man by reason cannot know God; he can only know about God. Through the light of reason certain important facts about God may be discovered. “Because that which may be known of God is manifest in them; for God hath showed it unto them. For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse.” Through the light of nature man’s moral reason may be enlightened, but the deeper mysteries of God remain hidden to him until he has received illumination from above. “But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.” When the Spirit illuminates the heart, then a part of the man sees that never saw before; a part of him knows that never knew before, and that with a kind of knowing that the most acute thinker cannot imitate. He knows now in a deep and authoritative way, and what he knows needs no reasoned proof. His experience of knowing is above reason, immediate, perfectly convincing and inwardly satisfying.
The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned. 1 Corinthians 2:14
When the Spirit illuminates the heart, then a part of the man sees that never saw before; a part of him knows that never knew before, and that with a kind of knowing that the most acute thinker cannot imitate.
Illuminate our hearts, Holy Spirit, so that we can see what we’ve never seen before and know what we’ve never known before.