What does 1 Corinthians 7:12 mean?

Paul is answering a question from the Corinthians about whether Christians should be married or have sex with their spouses (1 Corinthians 7:1). He has been clear: Marriage and sex within marriage are God's will for those who are already married. Christians married to each other should not get divorced, especially due to the false belief that being unmarried is more spiritual or pleasing to God than being married.

What if a Christian is married to an unbeliever? Should the Christian divorce an unsaved spouse? Paul answers that question in this and the following verses.

In the era when Paul wrote these words, Christianity was relatively new, and drastically opposed to the prevailing Greco-Roman culture. Much more so than in the modern world, it was quite common in the early church for converts to come to faith on their own, apart from their spouse. This would understandably create tension for the believer, joined in a union with Christ and with someone outside of Christ. Maybe, they thought, it would be better to dissolve that marriage and move on.

Paul says no. If a man is a Christian and married to an unbelieving woman, he should not divorce her, so long as she agrees to stay married to him. Paul will say in the following verses that if the unsaved spouse insists on divorce, however, the believer should allow it and will not be held accountable for the other person's abandonment (1 Corinthians 7:15).

He adds that this instruction comes from him and not directly from the Lord. This does not mean we should discount Paul's instruction as merely human advice. He writes these words under the inspiration of the Holy Spirit and as the commissioned representative of Christ. For that precise reason, he acknowledges that this specific principle has not been explicitly revealed to him directly by Christ, as some of his other teachings were. As inspired Scripture, however, readers would be unwise to dismiss it.