So anyone who speaks in tongues should pray also for the ability to interpret what has been said. For if I pray in tongues, my spirit is praying, but I don’t understand what I am saying. Well then, what shall I do? I will pray in the spirit, and I will also pray in words I understand. I will sing in the spirit, and I will also sing in words I understand.  For if you praise God only in the spirit, how can those who don’t understand you praise God along with you? How can they join you in giving thanks when they don’t understand what you are saying? You will be giving thanks very well, but it won’t strengthen the people who hear you. (1 Corinthians 14:13-17, NLT)

But if all of you are prophesying, and unbelievers or people who don’t understand these things come into your meeting, they will be convicted of sin and judged by what you say. As they listen, their secret thoughts will be exposed, and they will fall to their knees and worship God, declaring, “God is truly here among you.” (1 Corinthians 14:24-25)