Now we have received, not the spirit of the world, but the Spirit which is of God, that we may know the things which are freely given to us of God. Which also we speak, not in words taught by human wisdom, but in those taught by the Holy Spirit, explaining spiritual things by spiritual words. But the natural man receiveth not the things of the Spirit; for they are foolishness to him: neither can he know them, because they are spiritually discerned.read more.
But the spiritual man discerneth all things, while he himself is discerned by no man.

But strong meat belongeth to them of full age, to them who have their senses exercised by habit to discern both good and evil.

And be not conformed to this world, but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect will of God.

For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ.