In 1 Cor. 2:14 St. Paul describes the natural man as utterly devoid of spiritual perception. Spiritual realities "are foolishness unto him"; and "he cannot know them, because they are spiritually judged or examined" (R. V.). Christ foretold this state of things when he declared that "the world," the aggregate of natural men, "cannot receive the Spirit of truth, because they see him not." They have in exercise only sense-perception and reason, neither of which apprehends God and spiritual things. Spiritual intuition is an attribute of spiritual life; and spiritual life is absent, because unbelief bars out the Holy Spirit, the Lord and Giver of life. Hence, St. Jude describes "natural or sensual [animal, R. V. margin] men as having not the Spirit." Just the opposite is the characteristic of spiritual men, "Now we have received, not the spirit of the world, but the spirit which is of God, that we might know the things that are freely given to us of God." While the natural man is, by the perverse attitude of his will, an agnostic, the spiritual man is an epignostic, having a clear perception of divine realities, which he is enabled to speak of, not in the terms of groveling human philosophy, but in the words which the Spirit teacheth (1 Cor. 2:13, R. V., margin), "interpreting spiritual things to spiritual men."
— Half-Hours With St. Paul and Other Bible Readings Chapter 14.