In 1 Corinthians 14, Paul addresses the issue of ‘tongues’. Whatever people now might think these tongues were, it seems to me that Paul spoke of these ‘tongues’ as merely human languages.
Why do I say this? Corinth was a major, I mean major, centre of trade. All sorts of people and things passed through the city – literally – as it was at the neck of an isthmus. This geographical fact allowed the trade ships to save travelling time by being dragged across the thin section of land along a track. In this way they could pass quickly from the Aegean Sea to the western Mediterranean and back again. Lots of people with different mother-tongues (languages) lived and worked in the region.
Now it is true that Greek was the common language of the day, but even the New Testament gives us the heads-up that other languages were spoken at the time. In Lystra, after Paul healed a lame man by the authority of Jesus, the people of the city called out in the Lycaonian language that the gods had come to earth. Again, in Malta, the locals called the shipwrecked people ‘barbarians’, meaning they spoke a language that the Maltese did not readily understand. This is perhaps why Paul could tell the Corinthians that ‘he spoke in tongues more than all of them’ (1 Cor 14:18), due to his wide travelling. But this is the point. Paul insisted that things said in church – which is the context of 1 Cor. 14 – must be understood by as many people as possible. This would mean speaking, praying, singing etc., in a language understood by most people at a worship meeting.
Paul points out that a speaker who used an obscure language, rather than one commonly understood by the congregation, would only be understood by God at that time (1 Cor. 14:2). What the speaker says would be a mystery to others in the meeting. The speaker might be spiritual or passionate in his delivery, and his talk might be of help to himself, but nobody else would get it. This is not the way of love. Love edifies [builds up] others. This is why Paul desires people to prophesy. Now, this does not necessarily mean to ‘foretell the future’ or to reveal new information about Jesus. It most likely means to ‘forth tell’ or proclaim the message of Jesus that they had already received. Later, Paul himself speaks of delivering to them the Gospel that he himself had received (1 Cor. 15:3).
Paul’s aim was to have the church focused on the clear message regarding Jesus Christ: who he is, what he did, and what that means in all its fullness for sinners like us. Using a local language instead of the common language would make speaker and congregation ‘barbarians’ to one another (just as the Maltese were to the shipwrecked souls).
In v.6 Paul says that if he spoke to the Corinthians in a tongue, his talk would not benefit them, and in vs.14 to 17 he develops this idea. By praying in a tongue he himself would benefit but his prayer would not benefit [be unfruitful for] the congregation. His understanding, declared in a language unknown to his audience, would not benefit them. The same, he says, is true of his singing or giving thanks in a foreign language. No one else would be able to say ‘Amen’ to it. Instead, Paul would rather give a short sermon in a known language than a barrage of words no one understood. The aim is building up the church by clearly articulating the Gospel message.
One last point. Paul says when an unknown language is used toward a church, it is a sign of God’s displeasure at unbelief. This is indicated in verse 21. The passage is from Isaiah 28:11-12. The Old Testament church was refusing to listen to the Gospel. They were running after gods who were not gods and who could not save. They rejected God’s plain message to turn from sin and be save. So God told them that foreign conquerors, people who spoke a strange language, would come and speak to them, and show them by aggressive action that God meant what he had told them in plain language. We must listen to God. So, if a foreign language is ever used in church it must be translated so all can hear, understand and judge the message, or prayer or song. We are not to obscure the Gospel with our words.