Speaking in tongues had become a dominant feature in the Corinthian church. It appears that this gift was manifested in two ways: as the ability to speak known languages, as on the Day of Pentecost (Acts 2:6-12); and, as in these verses, making sounds which communicated from the person's heart to God without going through the limitations of language vocabulary and grammar.
 
The Corinthians thought that this ability was a sign of spiritual power and superiority; but however satisfying it was for the speaker to communicate with God in that way, it had no meaning to other human ears. Paul did not disregard this activity as a genuine spiritual gift, and said that he would like everybody to be able to express themselves to God in this intimate way, as he did (1 Corinthians 14:18). The problem was that nobody else in the church could benefit, unless the sounds were interpreted, and thus it could not build up the church.
 
But the believers should not shy away from spiritual gifts; indeed they should desire them. They should not despise personal encounters with God (1 Corinthians 14:39), but neither should they boast about their mystical experiences (2 Corinthians 12:7-9). Instead they should ask God to give them gifts which would enable other people to understand His will. Prophesying is a general term which includes teaching and preaching. It is designed to explain clearly to God's people what God likes and hates, and how to please Him. That will strengthen, encourage and comfort His people.
 
This teaching is still needed. Generally, we need to learn the principle that the Lord wants His church to grow up into maturity by understanding what He has said. There is a place for personal intimacy with the Lord but it should be just that: personal, as Jesus taught (Matthew 6:5-8). Public worship should be accessible to all and in a language they can understand. Whatever wonderful mystical experiences God may give to some people, understanding His will is even more important. However significant our personal encounters, the Lord wants to build the whole church. We should not get in the way by advertising our personal experiences and suppressing the teaching of His Word.