What does 1 Corinthians 14:21 mean?
As he so often does in his letters, Paul now quotes from one of the Old Testament prophets to make a connection between present circumstances and how God acted in the past. This time, he paraphrases Isaiah 28:11–12. In that passage, Israel had rejected God's clear and simple message to them in their own language. Soon He would speak to them through the Assyrians, people with "strange lips" and "foreign tongues." In other words, His messages to them would become less clear as a result of His judgment for their sin.Paul connected this to what was happening in Corinth. He is helping the Corinthians see that the clear teaching that comes from the practice of the gift of prophecy is better than the lack of meaning that results when the gift of tongues is used without an interpreter. Listeners may be impressed (or not) by a display of foreign languages, but they will not respond to the direction of the Lord because they will not be able to understand it.