“The one who speaks in a tongue builds himself up, but the one who prophesies builds up the church.”
1 Corinthians 14.4
In context Paul addresses the use of the gift of speaking in tongues without an interpreter. His statement is a criticism of selfish use of miraculous gifts. The goal is edification of all. That is the key word of the chapter.
Pentecostals take this phrase out of context as permission for their practice, which has nothing in common with the miraculous gift of the first century. How sad to turn it on its head!