1 Corinthians 7:14-16

14 For the unbelieving husband is made holy through his wife, and the unbelieving wife is made holy through the brother. Otherwise your children would be unclean, whereas in fact they are holy. [AD]

15 If the unbeliever separates, [9] however, let him separate. The brother or sister is not bound in such cases; God has called you to peace.

16 For how do you know, wife, whether you will save your husband; or how do you know, husband, whether you will save your wife?