1 Corinthians 14:10-12

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