1 Corinthians 7:13-16

13And if any [believing] woman has an unbelieving husband, and he consents to live with her, she must not leave him.

14For the unbelieving husband is sanctified [that is, he receives the blessings granted] through his [Christian] wife, and the unbelieving wife is sanctified through her believing husband. Otherwise your children would be [ceremonially] unclean, but as it is they are holy.

15But if the unbelieving partner leaves, let him leave. In such cases the [remaining] brother or sister is not [spiritually or morally] bound. But God has called us to peace.

16For how do you know, wife, whether you will save your husband [by leading him to Christ]? Or how do you know, husband, whether you will save your wife [by leading her to Christ]?