1 Corinthians 7:10-12

10I will say this to people who have married. (This is not my rule. It is a rule that comes from the Lord himself.) A wife must not leave her husband.

11But if she does leave him, she must not marry another man. Or she should go back to live with her husband. In the same way, a husband must not send his wife away.

12To all you other people, I say this. (This is what I think. The Lord has not spoken about it.) A Christian man may have a wife who does not believe in Christ. If she agrees to continue living with him, then he should not send her away.