Paul has given two instructions: stay with an unbelieving spouse who is pleased to stay, and let one go who chooses to leave (1 Corinthians 7:12-15). This question gives the reason behind them, and commentators hear it two ways. Barnes reads it as hope: a believer should not separate needlessly because of "the possibility or the probability that the unbelieving party might be converted." Gill sets out both readings: since you cannot know whether you will save your spouse, you need not cling at any cost to one who departs; or, you should seek peace, hoping your spouse may yet be won. Either way, the question is honest about what no husband or wife can know ahead of time.

Paul gives no yes or no, because the honest answer is that no one knows. He moves at once to a steady rule: "as the Lord hath called every one, so let him walk" (1 Corinthians 7:17). Earlier he had said that "the unbelieving husband is sanctified by the wife" (1 Corinthians 7:14) and that "God hath called us to peace" (1 Corinthians 7:15). The outcome is left with God while the believer lives faithfully where God has placed him or her.

The gospel came to Corinth among people who were already married, so one spouse might believe while the other did not. Paul is careful to separate the Lord's command (1 Corinthians 7:10) from his own counsel "to the rest" (1 Corinthians 7:12). The verb for "save" (sozo) is future tense here: literally, "whether you will save." Gill observes that "persons in such a relation have often great influence upon one another," and he pictures the unbelieving spouse as one "by whose conversation he may be won over," meaning by the believer's way of life.

Paul's question holds two truths together. A believing spouse has a real part to play in the salvation of the one they love, and yet no one can promise the result. Matthew Henry draws out the hopeful side: "Mere possibility of success should be a sufficient motive" to work for the salvation of those closest to us.

Barnes is clear about how that work is done: "Not by harshness or severity of manner," but "by tender entreaty, and mildness of life, and by prayer." The same hope appears in Peter's counsel that an unbelieving husband may be "won by the conversation of the wives" (1 Peter 3:1). A home can become a quiet place of witness, while the outcome stays in God's hands.