1 Corinthians 7:12-13, 15

To the rest I say (I, not the Lord) that if any brother has a wife who is an unbeliever, and she consents to live with him, he should not divorce her. If any woman has a husband who is an unbeliever, and he consents to live with her, she should not divorce him.

But if the unbelieving partner separates, let it be so. In such cases the brother or sister is not enslaved. God has called you to peace.