Problem: In two places in 1 Corinthians (7:12, 40), the Apostle Paul seems to imply that he is writing on his own authority, not the Lord’s.
First, in 7:12 Paul says, “But to the rest I, not the Lord.” And in 7:40 he says, “and I think I also have the Spirit of God,” which seems to imply that Paul is not sure if he has the Holy Spirit. How can these verses be harmonized with the divine authority claimed by Paul in his epistles (cf. Gal. 1:11-17; 2 Tim. 3:16-17)?
Solution: First, concerning 1 Corinthians 7:12, Paul is referring to the fact that the Lord did not directly address this issue when He spoke about divorce and marriage (Matt. 5:31-32; 19:4-12). So Paul does speak to it here, giving his authoritative view on whether a believing wife should stay with an unbelieving husband.
Second, Paul was not uncertain of his possession of the Holy Spirit on this matter, since he said clearly, “I also have the Spirit of God” (1 Cor 7:40). So this passage cannot be used to show that Paul disclaimed divine authority.
Finally, Paul clearly affirmed his divine authority in this verse book, declaring what he wrote as “words . . . the Holy Spirit teaches” (1 Cor 2:13). Indeed, he concludes the book by saying, “the things which I write to you are the commandments of the Lord” (14:37). So his words in chapter 7 should be taken in harmony with these emphatic claims.