For if I pray in an unknown tongue, my spirit prays, but my understanding is unproductive.
Let him who speaks in an unknown tongue pray that he may interpret.
Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue.
For he who speaks in an unknown tongue does not speak to men, but to God. For no one understands him, although in the spirit, he speaks mysteries.