1 Corinthians 7: 10-13 (NKJV)
Keep Your Marriage Vows
10 Now to the married I command, yet not I but the Lord: A wife is not to depart from her husband. 11 But even if she does depart, let her remain unmarried or be reconciled to her husband. And a husband is not to divorce his wife.
12 But to the rest I, not the Lord, say: If any brother has a wife who does not believe, and she is willing to live with him, let him not divorce her. 13 And a woman who has a husband who does not believe, if he is willing to live with her, let her not divorce him.