1 Corinthians 14:15-16
14:15 What should I do? I will pray with my spirit, but I will also pray with my mind. I will sing praises with my spirit, but I will also sing praises with my mind.
14:16 Otherwise, if you are praising God with your spirit, how can someone without the gift say “Amen” to your thanksgiving, since he does not know what you are saying?