1 Corinthians 7:11-15

(but if she does leave, she must remain unmarried, or else be reconciled to her husband), and that the husband is not to divorce his wife.

But to the rest I say, not the Lord, that if any brother has an unbelieving wife, and she consents to live with him, he must not divorce her.

And if any woman has an unbelieving husband, and he consents to live with her, she must not divorce her husband.

For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through her believing husband; for otherwise your children are unclean, but now they are holy.

Yet if the unbelieving one is leaving, let him leave; the brother or the sister is not under bondage in such cases, but God has called us in peace.