1 Corinthians 2:14-16

14But the natural [unbelieving] man does not accept the things [the teachings and revelations] of the Spirit of God, for they are foolishness [absurd and illogical] to him; and he is incapable of understanding them, because they are spiritually discerned and appreciated, [and he is unqualified to judge spiritual matters].

15But the spiritual man [the spiritually mature Christian] judges all things [questions, examines and applies what the Holy Spirit reveals], yet is himself judged by no one [the unbeliever cannot judge and understand the believer’s spiritual nature].

16For who has known the mind and purposes of the Lord, so as to instruct Him? But we have the mind of Christ [to be guided by His thoughts and purposes].