6 What is that “wedding garment” then? This is the wedding garment: “Now the end of the commandment,” says the Apostle, “is charity out of a pure heart, and of a good conscience, and of faith unfeigned.” This is “the wedding garment.” Not charity of any kind whatever; for very often they who are partakers together of an evil conscience seem to love one another. They who commit robberies together, who love the hurtful arts of sorceries, and the stage together, who join together in the shout of the chariot race, or the wild beast fight; these very often love one another; but in these there is no “charity out of a pure heart, and of a good conscience, and of faith unfeigned.
The wedding garment” is such charity as this. “Though I speak with the tongues of men and of Angels, and have not charity, I have become as sounding brass, and a tinkling cymbal.” Tongues have come in alone, and it is said to them, “How came ye in hither not having a wedding garment?” “Though,” said he, “I have the gift of prophecy, and understand all mysteries, and all knowledge, and though I have all faith, so that I could remove mountains, and have not charity, I am nothing.”
See, these are the miracles of men who very often have not “the wedding garment.” “Though,” he says, “I have all these, and have not Christ, I am nothing.” Is then “the gift of prophecy” nothing? Is then “the knowledge of mysteries” nothing? It is not that these are nothing; but “I,” if I have them, “and have not charity, am nothing.” How many good things profit nothing without this one good thing! If then I have not charity, though I bestow alms freely upon the poor, though I have come to the confession of Christ's Name even unto blood and fire, these things may be done even through the love of glory, and so are vain.
Because then they may be done even from the love of glory, and so be vain, and not through the rich charity of a godly affection, he names them all also in express terms, and you give ear to them; “though I distribute all my goods for the use of the poor, and though I give my body to be burned, and have not charity, it profits me nothing.” This then is “the wedding garment.” Question yourselves; if you have it, you may be without fear in the Feast of the Lord. In one and the same man there exist two things, charity and desire.
Let charity be born in you, if it be yet unborn, and if it be born, be it nourished, fostered, increased. But as to that desire, though in this life it cannot be utterly extinguished; “for if we say that we have no sin we deceive ourselves, and the truth is not in us;” but in so far as desire is in us, so far we are not without sin: let charity increase, desire decrease; that the one, that is, charity, may one day be perfected, and desire be consumed. Put on “the wedding garment:” you I address, who as yet have it not.
You are already within, already do ye approach to the Feast, and still have ye not yet the garment to do honour to the Bridegroom; “You are yet seeking your own things, not the things which are Jesus Christ's.” For “the wedding garment” is taken in honour of the union, the union, that is, of the Bridegroom to the Bride. You know the Bridegroom; it is Christ. You know the Bride; it is the Church. Pay honour to the Bride, pay honour to the Bridegroom. If you pay due honour to them both, you will be their children.
Therefore in this make progress. Love the Lord, and so learn to love yourselves; that when by loving the Lord you shall have loved yourselves, you may securely love your neighbour as yourselves. For when I find a man that does not love himself, how shall I commit his neighbour whom he should love as himself to him? And who is there, you will say, who does not love himself? Who is there? See, “He that loves iniquity hates his own soul.” Does he love himself, who loves his body, and hates his soul to his own hurt, to the hurt of both his body and soul? And who loves his own soul? He that loves God with all his heart and with all his mind. To such an one I would at once entrust his neighbour. “Love your neighbour as yourselves.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)