1 Corinthians 14:13–19 (ESV)
 Therefore, one who speaks in a tongue should pray that he may interpret.  For if I pray in a tongue, my spirit prays but my mind is unfruitful.  What am I to do? I will pray with my spirit, but I will pray with my mind also; I will sing praise with my spirit, but I will sing with my mind also.  Otherwise, if you give thanks with your spirit, how can anyone in the position of an outsider say “Amen” to your thanksgiving when he does not know what you are saying?  For you may be giving thanks well enough, but the other person is not being built up.  I thank God that I speak in tongues more than all of you.  Nevertheless, in church I would rather speak five words with my mind in order to instruct others, than ten thousand words in a tongue.