1 Corinthians 14:22-25
22So where does it get you, all this speaking in tongues no one understands? It doesn''t help believers, and it only gives unbelievers something to gawk at. Plain truth-speaking, on the other hand, goes straight to the heart of believers and doesn''t get in the way of unbelievers.
23If you come together as a congregation and some unbelieving outsiders walk in on you as you''re all praying in tongues, unintelligible to each other and to them, won''t they assume you''ve taken leave of your senses and get out of there as fast as they can?
24But if some unbelieving outsiders walk in on a service where people are speaking out God''s truth, the plain words will bring them up against the truth
25and probe their hearts. Before you know it, they''re going to be on their faces before God, recognizing that God is among you.h