1 Corinthians 14:13-22

Therefore let one who speaks in a tongue pray that he may [be gifted to] translate or explain [what he says]. For if I pray in a tongue, my spirit prays, but my mind is unproductive [because it does not understand what my spirit is praying]. Then what am I to do? I will pray with the spirit [by the Holy Spirit that is within me] and I will pray with the mind [using words I understand]; I will sing with the spirit [by the Holy Spirit that is within me] and I will sing with the mind [using words I understand]. Otherwise if you bless [and give thanks to God] in the spirit only, how will any outsider or someone who is not gifted [in spiritual matters] say the “Amen” [of agreement] to your thanksgiving, since he does not know what you are saying? [1 Chr 16:36; Ps 106:48] You are giving thanks well enough [in a way that God is glorified], but the other person [who does not understand you] is not edified [and spiritually strengthened since he cannot join in your thanksgiving]. I thank God that I speak in [unknown] tongues more than all of you; nevertheless, in public worship I would rather say five understandable words in order to instruct others, than ten thousand words in a tongue [which others cannot understand]. Brothers and sisters, do not be children [immature, childlike] in your thinking; be infants in [matters of] evil [completely innocent and inexperienced], but in your minds be mature [adults]. It is written in the Law, “BY MEN OF STRANGE TONGUES AND BY THE LIPS OF FOREIGNERS I WILL SPEAK TO THIS PEOPLE, AND NOT EVEN THEN WILL THEY LISTEN TO ME,” says the Lord. [Is 28:11, 12] Therefore, [unknown] tongues are [meant] for a [supernatural] sign, not to believers but to unbelievers [who might be receptive]; while prophecy [foretelling the future, speaking a new message from God to the people] is not for unbelievers but for believers.