1 Corinthians 2:14

Now the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him; and he cannot know them, because they are spiritually judged. [As sound is perceived by the ear, and not by the eye, so the spirit of man perceives spiritual things which can not be comprehended by his psychic nature. But a man who has lived on the low psychic plane--a carnal, sensuous victim to bodily appetites--has, by neglect, let his spiritual faculties become so torpid, and by sin so deadened them, that the spiritual things of God become as foolishness to him, despite their worthiness-- 1 Timothy 1:15]