1 Corinthians 14:9-19

9So it is with you, if you speak words [in an unknown tongue] that are not intelligible and clear, how will anyone understand what you are saying? You will be talking into the air [wasting your breath]!

10There are, I suppose, a great many kinds of languages in the world [unknown to us], and none is lacking in meaning.

11But if I do not know the meaning of the language, I will [appear to] be a foreigner to the one who is speaking [since he knows exactly what he is saying], and the one who is speaking will [appear to] be a foreigner to me.

12So it is with you, since you are so very eager to have spiritual gifts and manifestations of the Spirit, strive to excel in ways that will build up the church [spiritually].

13Therefore let one who speaks in a tongue pray that he may [be gifted to] translate or explain [what he says].

14For if I pray in a tongue, my spirit prays, but my mind is unproductive [because it does not understand what my spirit is praying].

15Then what am I to do? I will pray with the spirit [by the Holy Spirit that is within me] and I will pray with the mind [using words I understand]; I will sing with the spirit [by the Holy Spirit that is within me] and I will sing with the mind [using words I understand].

16Otherwise if you bless [and give thanks to God] in the spirit only, how will any outsider or someone who is not gifted [in spiritual matters] say the “Amen” [of agreement] to your thanksgiving, since he does not know what you are saying?

17You are giving thanks well enough [in a way that God is glorified], but the other person [who does not understand you] is not edified [and spiritually strengthened since he cannot join in your thanksgiving].

18I thank God that I speak in [unknown] tongues more than all of you;

19nevertheless, in public worship I would rather say five understandable words in order to instruct others, than ten thousand words in a tongue [which others cannot understand].