John 15:10

(Tract. lxxxii. 1) Made bright or glorified; the Greek word may be translated in either way. Δόξα signifies glory; not our own glory, we must remember, as if we had it of ourselves: it is of His grace that we have it; and therefore it is not our own but His glory. For from whom shall we derive our fruitfulness, but from His mercy preventing us. Wherefore He adds, As My Father hath loved Me, even so love I you. This then is the source of our good works. Our good works proceed from faith which worketh by love: but we could not love unless we were loved first: As My Father hath loved Me, even so love I you. This does not prove that our nature is equal to His, as His is to the Father's, but the grace, whereby He is the Mediator between God and man, the man Christ Jesus. The Father loves us, but in Him. (Tract. lxxxii. 3. et seq.) Who doubts that love precedes the observance of the commandments? For who loves not, has not that whereby to keep the commandments. These words then do not declare whence love arises, but how it is shown, that no one might deceive himself into thinking that he loved our Lord, when he did not keep His commandments. Though the words, Continue ye in My love, do not of themselves make it evident which love He means, ours to Him, or His to us, yet the preceding words do: I love you, He says: and then immediately after, Continue ye in My love. Continue ye in My love, then, is, continue in My grace: and, If ye keep My commandments, ye shall abide in My love, is, Your keeping of My commandments, will be evidence to you that ye abide in My love. It is not that we keep His commandments first, and that then He loves; but that He loves us, and then we keep His commandments. This is that grace, which is revealed to the humble, but hidden from the proud. But what means the next words, Even as I have kept My Father's commandments, and abide in His love: i. e. […]

But what are we to make of that which follows: "Even as I have kept my Father's commandments, and abide in His love"? Here also He certainly intended us to understand that fatherly love wherewith He was loved of the Father. For this was what He has just said, "As the Father hath loved me, so have I loved you;" and then to these He added the words, "Continue ye in my love;" in that, doubtless, wherewith I have loved you. Accordingly, when He says also of the Father, "I abide in His love," we are to understand it of that love which was borne Him by the Father. But then, in this case also, is that love which the Father bears to the Son referable to the same grace as that wherewith we are loved of the Son: seeing that we on our part are sons, not by nature, but by grace; while the Only-begotten is so by nature and not by grace? Or is this even in the Son Himself to be referred to His condition as man? Certainly so. For in saying, "As the Father hath loved me, so have I loved you," He pointed to the grace that was His as Mediator. For Christ Jesus is the Mediator between God and men, not in respect to His Godhead, but in respect to His manhood. And certainly it is in reference to this His human nature that we read, "And Jesus increased in wisdom and age, and in favor [grace] with God and men." In harmony, therefore, with this, we may rightly say that while human nature belongs not to the nature of God, yet such human nature does by grace belong to the person of the only-begotten Son of God; and that by grace so great, that there is none greater, yea, none that even approaches equality. For there were no merits that preceded that assumption of humanity, but all His merits began with that very assumption. The Son, therefore, abideth in the love wherewith the Father hath loved Him, and so hath kept His commandments. […]

For he who holds, without pride and boasting, the true glory (opinion) regarding created things and the Creator, who is the Almighty God of all, and who has granted existence to all; [such an one,] continuing in His love and subjection, and giving of thanks, shall also receive from Him the greater glory of promotion, looking forward to the time when he shall become like Him who died for him, for He, too, "was made in the likeness of sinful flesh," to condemn sin, and to cast it, as now a condemned thing, away beyond the flesh, but that He might call man forth into His own likeness, assigning him as [His own] imitator to God, and imposing on him His Father's law, in order that he may see God, and granting him power to receive the Father; [being] the Word of God who dwelt in man, and became the Son of man, that He might accustom man to receive God, and God to dwell in man, according to the good pleasure of the Father.

Now, if observing the commandments is the essential sign of love, it is very greatly feared that without love even the most effective action of the glorious gifts of grace—even of the most sublime powers and even of faith itself and the commandment that make a person perfect—will not be of help.… It is evident, therefore, and undeniable that without charity—even though ordinances are obeyed and righteous acts are performed, even though the commandments of the Lord have been observed and great wonders of grace effected—they will be considered as works of iniquity … because those who perform these acts have as their aim the gratification of their own will.

And how shall this be? "If ye keep My commandments, even as I have kept my Father's commandments." Again, His discourse proceedeth in a human way; for certainly the Lawgiver would not be subject to commandments. Seest thou that here also, as I am always saying, this is declared because of the infirmity of the hearers?