14:20–25 Up to this point, Paul has been discussing the use of tongues among believers. But what about unbelievers who hear the tongues? The Corinthians have ignored them, and Paul admonishes the church for this display of spiritual immaturity. He appeals to “the Law,” (the Old Testament) to show that God uses unintelligible speech as a sign of judgment. Is. 28:11 explains how God judged the Israelites through Assyrians speaking a foreign language. If non-Christians come to the worship and hear an unintelligible language, they will be repelled (v. 23) and reject the gospel. In this situation uninterpreted tongues are a sign of judgment “for unbelievers” (v. 22). But the Corinthians should aim at bringing unbelievers to repentance and to the recognition that God is present (v. 25). Because God uses the understandable words of prophecy to accomplish this purpose, prophecy is a sign “for believers”; it is evidence of God’s goodness to them (v. 22).