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.
All Commentaries on 1 Corinthians 7:14 Go To 1 Corinthians 7
John Chrysostom
AD 407
If a man joined to a harlot is one body with her, then it is clear that a woman joined to an idolater is one body with him. That is true, but in this case she does not become unclean as a result. On the contrary, her cleanness overcomes the uncleanness of her husband, just as the cleanness of a believing husband overcomes the uncleanness of his unbelieving wife. How can this be, if a husband is not condemned for casting out a wife who has played the harlot? The reason is that in this case there is hope that the lost member may be saved through the marriage, whereas in the other case, the marriage has already been dissolved through harlotry. An unbelieving man may be reclaimed by his believing wife if she is faithful to him. But for a harlot things are not so easy, because how can she reclaim someone whom she has wronged? The same is true for a believing husband who has an unbelieving wife.