1 Corinthians 7:12–15

12 Now, I will speak to the rest of you, though I do not have a direct command from the Lord. If a Christian man* has a wife who is not a believer and she is willing to continue living with him, he must not leave her. 13 And if a Christian woman has a husband who is not a believer and he is willing to continue living with her, she must not leave him. 14 For the Christian wife brings holiness to her marriage, and the Christian husband* brings holiness to his marriage. Otherwise, your children would not be holy, but now they are holy. 15 (But if the husband or wife who isn’t a believer insists on leaving, let them go. In such cases the Christian husband or wife* is no longer bound to the other, for God has called you* to live in peace.)