1 Corinthians 14:1, 4, 22

Follow after charity, and desire spiritual gifts, but rather that ye may prophesy.

He that speaketh in an unknown tongue edifieth himself; but he that prophesieth edifieth the church.

Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe.