What is the context?
Paul calls for mature thinking while remaining innocent of evil. His quotation comes from Isaiah 28:11–12, where people who would not listen to God hear foreign speech instead. In its setting, that speech belongs to a warning of judgment. A striking sign is not automatically a mark of God’s approval.
The next comparison shows why the effect on listeners matters. If the whole church speaks in tongues and outsiders cannot understand, they may conclude the people are out of their minds. A sign can confront someone without bringing that person to understanding or faith.
By contrast, understandable prophetic speech can expose a visitor’s heart, bring conviction and lead to worship of God. Calling prophecy a gift for believers does not mean an unbeliever can never benefit from hearing it; Paul immediately describes that very possibility.
These are contrasting situations meant to guide the church’s choices. They do not promise that every visitor will respond identically, or give a speaker permission to invent private information about someone. The desired outcome is recognition of God’s presence, rather than amazement at a person’s performance.
How is this passage commonly understood?
Christians commonly recognize the contrast between an outsider’s confusion and being brought to conviction. They explain the sign language in different ways.
Calvin’s comment on verse 22 considers both a warning of judgment connected with Isaiah and a miraculous sign directed toward unbelievers. Wesley’s note emphasizes the sign drawing unbelievers’ attention to God’s message. The USCCB note on verses 20–22 emphasizes Isaiah’s warning against unbelief, distinguishing the faithless people addressed there from the outside visitors in verses 23–25.
These readings give different weight to the sign’s warning and witness. All must account for Paul’s practical conclusion: speech in the assembly should help people hear and respond to God, rather than leave them unable to understand.
Where does this fit in God's plan?
An earlier parallel appears in Zechariah 8:20–23: people from different nations seek the Lord because they have heard that God is with His people. Paul’s picture of a visitor acknowledging God among the Corinthians has that same theme of God’s presence drawing people to worship.
This is a parallel in the response to God’s presence, not a claim that every detail of Zechariah’s promise is exhausted in Corinth. The larger purpose includes people coming to know the Lord. The way a congregation uses its gifts should serve that purpose.
What is our position?
We don't have a position on this passage yet. When our study reaches a conclusion the text supports, it will appear here.