3 According to a certain respect then they were evil, who after another respect were good. For to them to whom it is said, “You being evil know how to give good gifts unto your children;” is added immediately, “How much more shall your Father which is in heaven?” He is then the Father of the evil, but not of those who are to be left so; because He is the Physician of them who are to be cured. According to a certain sort then they were evil. And yet those guests of the Householder at the King's marriage, were not I suppose of that number of whom it was said, “they invited good and bad,” that they should be reckoned among the number of the bad, who we have heard were shut out in his person who was found not to have a wedding garment.
According to a certain respect, I repeat they were bad, who yet were good; and according to a certain respect they were good, who yet were bad. Hear John according to what respect they were bad: “If we say that we have no sin, we deceive ourselves, and the truth is not in us.” Behold after what respect they were bad: because they had sin. According to what respect were they good? “If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.” If then we should say, on the principle of this interpretation which you have now heard me bring, as I think, out of the sacred Scriptures, viz. that the same men are both after a certain manner, good, and after a certain manner bad; if we should wish to receive according to this sense the words, “they invited good and bad,” the same persons, that is, at once good and bad; if we should wish so to receive them, we are not permitted so to do, by reason of that one who was found “not having a wedding garment,” and who was not merely “cast forth,” so as to be deprived of that feast, but so as to be condemned in the punishment of everlasting darkness.
Source: Sermons on Selected Lessons of the New Testament (New Advent)