¹³ Therefore, he who speaks in a tongue should pray for the power to interpret. ¹⁴ For if I pray in a tongue, my spirit prays but my mind is unfruitful. ¹⁵ What am I to do? I will pray with the spirit and I will pray with the mind also; I will sing with the spirit and I will sing with the mind also. ¹⁶ Otherwise, if you bless^[a] with the spirit, how can any one in the position of an outsider^[b] say the “Amen” to your thanksgiving when he does not know what you are saying? ¹⁷ For you may give thanks well enough, but the other man is not edified. ¹⁸ I thank God that I speak in tongues more than you all; ¹⁹ nevertheless, in church I would rather speak five words with my mind, in order to instruct others, than ten thousand words in a tongue.

²⁰ Brethren, do not be children in your thinking; be babes in evil, but in thinking be mature. ²¹ In the law it is written, “By men of strange tongues and by the lips of foreigners will I speak to this people, and even then they will not listen to me, says the Lord.” ²² Thus, tongues are a sign not for believers but for unbelievers, while prophecy is not for unbelievers but for believers. ²³ If, therefore, the whole church assembles and all speak in tongues, and outsiders or unbelievers enter, will they not say that you are mad? ²⁴ But if all prophesy, and an unbeliever or outsider enters, he is convicted by all, he is called to account by all, ²⁵ the secrets of his heart are disclosed; and so, falling on his face, he will worship God and declare that God is really among you.