1 Corinthians 2:14-15

But 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]. But 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].