'Discern' in the Bible

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].

Do you not know and understand that you [the church] are the temple of God, and that the Spirit of God dwells [permanently] in you [collectively and individually]?

and to another the working of miracles, and to another prophecy [foretelling the future, speaking a new message from God to the people], and to another discernment of spirits [the ability to distinguish sound, godly doctrine from the deceptive doctrine of man-made religions and cults], to another various kinds of [unknown] tongues, and to another interpretation of tongues.

Let two or three prophets speak [as inspired by the Holy Spirit], while the rest pay attention and weigh carefully what is said.