7:10 yet not I. In this case, Paul was not citing his own divinely-inspired authority for his teaching (as in I Corinthians 7:6, 12), but to a specific teaching of Scripture (e.g., Genesis 2:24; Matthew 19:3-6). The Lord had already established and commanded the marriage relation to be permanent.

7:12 not the Lord. Again Paul is claiming, not disclaiming, divine authority for his teaching. In fact, he is even boldly superseding a command given by God through Ezra to the Jews. After returning from their captivity in Babylon, the Jews had taken wives from the unbelieving people of the land, and God told them: “Separate yourselves from the people of the land, and from the strange [i.e., foreign] wives” (Ezra 10:11). In the Christian context, however, a Christian is commanded not to divorce a non-Christian spouse, as long as the latter is willing to remain in the marriage.

7:14 now are they holy. If one member of the marriage is a believer, then he or she has been “sanctified”—that is, “set apart” in a special relation—unto God. By that very fact, then both the unbelieving spouse and their children have also been “set apart,” inevitably sharing some of the blessings that God promises the believing partner. The most obvious such blessing is the greater possibility that the children, as well as the non-Christian spouse, will be won to Christ by the believing spouse (I Corinthians 7:16).

7:15 bondage in such cases. If the unbelieving husband or wife chooses to leave the relationship, however, there remains nothing else the believer can do. The Christian spouse should remain unmarried (I Corinthians 7:11) as long as there is any possibility of reconciliation. Otherwise he or she “is not under bondage”—that is, no longer bound by the law to remain with the other spouse. The situation seems analogous to that in which one partner dies. “If the husband be dead, she is loosed from the law of her husband…so that she is no adulteress, though she be married to another man” (Romans 7:2-3). Once the ex-husband or ex-wife marries another, then the previous marriage relation is as permanently severed as if it had been severed by death, with no further possibility of reconciliation. When that becomes the case, it seems plain that there is no further “bondage” of any sort, so that the believer is free to remarry—but, of course, only “in the Lord” (I Corinthians 7:39).