Paul now addresses the spouse married to an unbeliever. The married are to remain married but if there’s desertion or divorce they are to remain as they are and not cling to another. To the unmarried, they are to remain single, but if they lack self-control, they are to marry. To the married who are with an unbelieving spouse Paul says:
12 But to the rest I say, not the Lord, that if any brother has a wife who is an unbeliever, and she consents to live with him, he must not divorce her. 13 And a woman who has an unbelieving husband, and he consents to live with her, she must not send her husband away.
For Paul, when one spouse converts to Christ it’s their duty to stay together and not divorce because of conversion so long as the spouse consents to live together. This issue was difficult then and remains unto today. Emotions run high, words are spoken, insults are unleashed, and at times physical abuse occurs. This can be a difficulty and tricky situation to navigate but there’s a reason for the command:
14 For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through her believing husband; for otherwise your children are unclean, but now they are holy.
Puzzling as it may be, here’s my best shot at getting the point. Biblically one is not redeemed because of another’s trust in the living God. For personal repentance is required of each one to be rescued from God’s wrath.
Second, the allusion to “unclean” and “holy” are OT themes where being set apart is a sign that one is part of the covenant community and thus males were to be circumcised, the people were to eat kosher foods, etc.
Third, taking part of said activities were signs one was part of the covenant community but did not guarantee one was part of the remnant (i.e., real regenerated believers in heart evidenced by their obedience to Yahweh). That is, not all Israel was saved evidenced by their recalcitrant lives and while their lineage is Jewish not all were sons of Abraham (i.e., not all had the faith of Abraham).
Fourth, as it was then, so it is today where people partake of the covenant community’s activities but remain unbelievers. So, what does Paul mean by “unclean and holy”? Perhaps being around the believing community does offer an opportunity for genuine faith to arise in both spouse and children. Again, even if they don’ have genuine saving faith, the Christian theist’s worldview has an impact on them that aids mirroring the image of God and somehow they are “clean and holy”
This text is tough to decipher, nevertheless when a text in Scripture is puzzling, the wise way to proceed is to use what is clearest in Scripture to deal with and try to understand the more difficult passages. Paul continues:
15 Yet if the unbelieving one leaves, let him leave; the brother or the sister is not under bondage in such cases, but God has called us to peace. 16 For how do you know, O wife, whether you will save your husband? Or how do you know, O husband, whether you will save your wife?
Paul notes several things here. First, the previous verses on “clean and holy” can’t mean someone is in the covenant family because he addresses the issue of “saving” one’s spouse. Personal repentance and faith is a necessary condition for salvation, thus one can’t be “saved” on another’s faith in Christ (e.g., your parents faith).
Second, Paul wants believers to understand that in this present evil age, believers married to non-believers will at times experience desertion or divorce.
Third, sometimes spouses believe that if they persevere in the marriage they will be able to save their spouse via example, but Paul reminds them that this is never a guarantee. It may happen, but it may not.
Fourth, the bondage that such a believer may experience is not what God has designed for them but instead His peace. What could this mean? Minimally, once we were God’s enemies but now are his friends because of Christ, wrath is no longer ours to bear. This peace is to be mirrored in our relationships. He’s saying, “If they want to leave, let them go and cling to Christ”.