1 Corinthians 14:6-19

So now, brothers and sisters, if I come to you speaking in tongues, how will I benefit you unless I speak to you with a revelation  or knowledge or prophecy or teaching? Even lifeless instruments that produce sounds — whether flute or harp   — if they don’t make a distinction in the notes, how will what is played on the flute or harp be recognized? In fact, if the bugle makes an unclear sound, who will prepare for battle?  In the same way, unless you use your tongue for intelligible speech, how will what is spoken be known? For you will be speaking into the air. There are doubtless many different kinds of languages in the world, none is without meaning. Therefore, if I do not know the meaning of the language, I will be a foreigner  to the speaker, and the speaker will be a foreigner to me. So also you — since you are zealous  for spiritual gifts,  , seek to excel in building up the church. Therefore the person who speaks in a tongue should pray that he can interpret. For if I pray in a tongue, my spirit  prays, but my understanding is unfruitful.  What then? I will pray with the spirit, and I will also pray with my understanding. I will sing praise with the spirit, and I will also sing praise with my understanding. Otherwise, if you praise with the spirit,  how will the outsider  say “Amen”  at your giving of thanks, since he does not know what you are saying? For you may very well be giving thanks, but the other person is not being built up. I thank  God that I speak in tongues more than all of you; yet in the church I would rather speak five words  with my understanding, in order to teach others also, than ten thousand words in a tongue.