1 Corinthians 7:13-15 (KJV)
13 And the woman which hath an husband that believeth not, and if he be pleased to dwell with her, let her not leave him.
14 For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy.
15 But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace.