1 Corinthians 14:1, 4, 22

You should seek after love, and you should truly want to have the spiritual gifts, especially the gift of prophecy.

The ones who speak in different languages are helping only themselves, but those who prophesy are helping the whole church.

So the gift of speaking in different kinds of languages is a sign for those who do not believe, not for those who do believe. And prophecy is for people who believe, not for those who do not believe.