1 Corinthians 7:12-13, 15

To the rest I say, which is not a saying of the Lord, if a brother has an unbelieving wife and she is content to live with him, he should not divorce her. And if a woman has a husband who is not a believer and he is content to live with her, she should not divorce him.

But if the unbelieving spouse wants a divorce, then let it be so. In this situation the believing spouse is not bound to the marriage, for God has called us to live in peace.