A Puzzling Pauline Paragraph
Paul’s goal in this paragraph is simple: he wants the Corinthians to grow up. Having a childlike innocence with respect to evil is a good thing, but in their thinking they need to stop being children and start being adults (20). The child/adult comparison has already appeared twice in this letter (4:14; 13:11), and in the second of these it contrasted maturity with immaturity, which is what it does here. By running after the gift of languages without regard for the edification or understanding of anyone else, the Corinthians are being childish, like a toddler so obsessed with enjoying their toys that they never think about anyone else.
Then comes the quotation from the Old Testament (Paul sometimes says “the Law” to refer to the Hebrew Scriptures as a whole), which makes sense of what Paul is doing (21). It comes from Isaiah 28:11-12, which is a passage pronouncing judgment over unbelieving Israel, seven centuries before. Because of Israel’s sin, Isaiah says, God will judge them by speaking to them through foreigners who will rule over them—Assyrians, then Babylonians, Persians, and eventually Greeks and Romans—in languages that they do not understand. Prophecy, meanwhile, will reassure them of God’s continued presence among them, not least through Isaiah’s own words.
So when Paul says that “tongues are a sign, not for believers but for unbelievers” (21), he is talking about a sign of judgment. He is saying that the experience of being spoken to in languages you do not understand serves to emphasise your distance from God, like it did for Israel. It creates a sense of alienation in the hearer—in contrast to prophecy, which emphasises how present God is. So by speaking in uninterpreted tongues in the church, the Corinthians are (unintentionally) pronouncing judgment over one another. They are making people feel further away from God, and from each other, rather than closer. If you have ever been in a meeting where everyone is speaking in tongues and you don’t, you may know what that feels like.
A clue that we are on the right lines here is the word “so” (oun) at the start of verse 23. If we take the phrase “a sign for unbelievers” as a good thing, which we should embrace, then that little word “so” makes no sense: Paul is saying completely different things in the two sentences. But if we take “a sign for unbelievers” as a sign of judgment, which we should avoid if at all possible, it makes perfect sense. Both verses are trying to prevent the Corinthians babbling away in languages that nobody understands, because it will make Christians feel judged by God and alienated from one another (22), and because it will make unbelievers think they are all crazy (23). Prophecy, on the other hand, is edifying to believers (3, 5), and has the capacity to convince unbelievers of their sin, expose the secrets of their hearts, reveal the presence of God, and cause them to fall face down in worship (24-25).