John 15:17

"These things I command you, that ye love one another." That is, "It is not to upbraid, that I tell you that I lay down My life for you, or that I ran to meet you, but in order to lead you into friendship." Then, since the being persecuted and insulted by the many, was a grievous and intolerable thing, and enough to humble even a lofty soul, therefore, after having said ten thousand things first, Christ entered upon this matter. Having first smoothed their minds, He thus proceedeth to these points, showing that these things too were for their exceeding advantage, as He had also shown that the others were. For as He had told them that they ought not to grieve, but rather to rejoice, "because I go to the Father," (since He did this not as deserting but as greatly loving them,) so here also He showeth that they ought to rejoice, not grieve.

(Tract. lxxxvii. 1) Our Lord had said, I have ordained that ye should walk, and bring forth fruit. Love is this fruit. Wherefore He proceeds: These things I command you, that ye love one another. (Gal. 5:22) Hence the Apostle saith: The fruit of the Spirit is love; and enumerates all other graces as springing from this source. Well then doth our Lord commend love, as if it were the only thing commanded: seeing that without it nothing can profit, with it nothing be wanting, whereby a man is made good.

In the Gospel lesson which precedes this one, the Lord had said: "Ye have not chosen me, but I have chosen you, and appointed you, that ye should go and bring forth fruit, and [that] your fruit should remain; that whatsoever ye shall ask of the Father in my name, He may give it you." On these words you remember that we have already discoursed, as the Lord enabled us. But here, that is, in the succeeding lesson which you have heard read, He says: "These things I command you, that ye love one another." And thereby we are to understand that this is our fruit, of which He had said, "I have chosen you, that ye should go and bring forth fruit, and [that] your fruit should remain." And what He subjoined, "That whatsoever ye shall ask of the Father in my name, He may give it you," He will certainly give us if we love one another; seeing that this very thing He has also given us, in choosing us when we had no fruit, because we had chosen Him not; and appointing us that we should bring forth fruit,-that is, that we should love one another,-a fruit that we cannot have apart from Him, just as the branches can do nothing apart from the vine. Our fruit, therefore, is charity, which the apostle explains to be, "Out of a pure heart, and a good conscience, and faith unfeigned." So love we one another, and so love we God. For it would be with no true love that we loved one another, if we loved not God. For every one loves his neighbor as himself if he loves God; and if he loves not God, he loves not himself. For on these two commandments of love hang all the law and the prophets: this is our fruit. And it is in reference, therefore, to such fruit that He gives us commandment when He says, "These things I command you, that ye love one another." In the same way also the Apostle Paul, when wishing to commend the fruit of the Spirit in opposition to the deeds of the flesh, posited this as his principle, saying, "The fruit of the Spirit is love;" and then, as if springing from and bound up in this principle, he wove the others together, which are "joy, peace, long-suffering, kindness, goodness, faith, meekness, temperance." For who can truly rejoice who loves not good as the source of his joy? Who can have true peace, if he have it not with one whom he truly loves? Who can be long-enduring through persevering continuance in good, save through fervent love? Who can be kind, if he love not the person he is aiding? Who can be good, if he is not made so by loving? Who can be sound in the faith, without that faith which worketh by love? Whose meekness can be beneficial in character, if not regulated by love? And who will abstain from that which is debasing, if he love not that which dignifies? Appropriately, therefore, does the good Master so frequently commend love, as the only thing needing to be commended, without which all other good things can be of no avail, and which cannot be possessed without bringing with it those other good things that make a man truly good.

They observed it in order to calumniate it, as we read in the Psalms, The ungodly seeth the righteous.