Chrysostom held to the legitimacy interpretation of 1 Cor. 7:14.
Ver. 12. “But to the rest speak I, not the Lord. If any brother have a wife that believeth not, and she is content to dwell with him, let him not leave her. And if any woman hath an husband that believeth not, and he is content to dwell with her, let her not leave him.”
For as when discoursing about separating from fornicators, he made the matter easy by the correction which he applied to his words, saying, “Howbeit, not altogether with the fornicators of this world;” so also in this case he provideth for the abundant easiness of the duty, saying, “If any wife have a husband, or husband a wife, that believeth not, let him not leave her.” What sayest thou? “If he be an unbeliever, let him remain with the wife, but not if he be a fornicator? And yet fornication is a less sin than unbelief.” I grant, fornication is a less sin: but God spares thine infirmities extremely. And this is what He doth about the sacrifice, saying, (S. Matt. v. 24.) “Leave the sacrifice, and be reconciled to thy brother.” This also in the case of the man who owed ten thousand talents. For him too He did not punish for owing him ten thousand talents, but for demanding back a hundred pence from his fellow-servant He took vengeance on him.
Then lest the woman might fear, as though she became unclean because of intercourse with her husband, he says, “For the unbelieving husband is sanctified in the wife, and the unbelieving wife is sanctified in the husband.” And yet, if “he that is joined to an harlot is one body,” it is quite clear that the woman also who is joined to an idolater is one body. Well: it is one body; nevertheless she becomes not unclean, but the cleanness of the wife overcomes the uncleanness of the husband; and again, the cleanness of the believing husband overcomes the uncleanness of the unbelieving wife.
How then in this case is the uncleanness overcome, and therefore the intercourse allowed; while in the woman who prostitutes herself, the husband is not condemned in casting her out? Because here there is hope that the lost member may be saved through the marriage; but in the other case the marriage has already been dissolved; and there again both are corrupted; but here the fault is in one only of the two. I mean something like this: she that has been guilty of fornication is utterly abominable: if then “he that is joined to an harlot is one body,” he also becomes abominable by having connection with an harlot; wherefore all the purity flits away. But in the case before us it is not so. But how? The idolater is unclean but the woman is not unclean. For if indeed she were a partner with him in that wherein he is unclean, I mean his impiety, she herself would also become unclean. But now the idolater is unclean in one way, and the wife holds communion with him in another wherein he is not unclean. For marriage and mixture of bodies is that wherein the communion consists.
Again, there is a hope that this man may be reclaimed by his wife for she is made completely his own: but for the other it is not very easy. For how will she who dishonored him in former times and became another’s and destroyed the rights of marriage, have power to reclaim him whom she had wronged; him, moreover, who still remains to her as an alien?
Again in that case, after the fornication the husband is not a husband: but here, although the wife be an idolatress, the husband’s rights are not destroyed.
However, he doth not simply recommend cohabitation with the unbeliever, but with the qualification that he wills it. Wherefore he said, “And he himself be content to dwell with her.” For, tell me, what harm is there when the duties of piety remain unimpaired and there are good hopes about the unbeliever, that those already joined should so abide and not bring in occasions of unnecessary warfare? For the question now is not about those who have never yet come together, but about those who are already joined. He did not say, If any one wish to take an unbelieving wife, but, “If any one hath an unbelieving wife.” Which means, If any after marrying or being married have received the word of godliness, and then the other party which had continued in unbelief still yearn for them to dwell together, let not the marriage be broken off. “For,” saith he, “the unbelieving husband is sanctified in the wife.” So great is the superabundance of thy purity.
What then, is the Greek holy? Certainly not: for he said not, He is holy; but, “He is sanctified in his wife.” And this he said, not to signify that he is holy, but to deliver the woman as completely as possible from her fear and lead the man to desire the truth. For the uncleanness is not in the bodies wherein there is communion, but in the mind and the thoughts. And here follows the proof; namely, that if thou continuing unclean have offspring, the child, not being of thee alone, is of course unclean or half clean. But now it is not unclean. To which effect he adds, “else were your children unclean; but now are they holy;” that is, not unclean. But the Apostle calls them, “holy,” by the intensity of the expression again casting out the dread arising from that sort of suspicion.