1 Corinthians 14

As Paul taught concerning the "gift of tongues", he comments -

"I thank my God, I speak with tongues more than ye all:
19 Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue."  (1 Corinthians 14:18–19)

For -

"...he that prophesieth speaketh unto men to edification, and exhortation, and comfort."  (1 Corinthians 14:3)

I believe that this is the reason for the gifts of the Spirit.