4 Bible Verses about Discernment, Source Of

Now we have not received the spirit that belongs to the world but the Spirit that comes from God, that we may get an insight into the blessings God has graciously given us. These truths we are setting forth, not in words that man's wisdom teaches but in words that the Spirit teaches, in this way fitting spiritual words to spiritual truths. An unspiritual man does not accept the things that the Spirit of God teaches, for they are nonsense to him; and he cannot understand them, because they are appreciated by spiritual insight.read more.
But the spiritual man appreciates everything, and yet he himself is not really appreciated by anybody.

But solid food belongs to full-grown men who on account of constant use have their faculties trained to distinguish good and evil.

Stop living in accordance with the customs of this world, but by the new ideals that mold your minds continue to transform yourselves, so as to find and follow God's will; that is, what is good, well-pleasing to Him, and perfect.

For who has ever known the Lord's thoughts, so that he can instruct Him? But we now possess Christ's thoughts.