1 The Lord, when promising that He would send the Holy Spirit, said, “When He has come, He will reprove the world of sin, and of righteousness, and of judgment.” What does it mean? Is it that the Lord Jesus Christ did not reprove the world of sin, when He said, “If I had not come and spoken unto them, they had not had sin; but now they have no cloak for their sin”? And that no one may take it to his head to say that this applied properly to the Jews, and not to the world, did He not say in another place, “If you were of the world, the world would love his own”? Did He not reprove it of righteousness, when He said, “O righteous Father, the world has not known You”? And did He not reprove it of judgment when He declared that He would say to those on the left hand, “Depart ye into everlasting fire, prepared for the devil and his angels”? And many other passages are to be found in the holy evangel, where Christ reproves the world of these things. Why is it, then, He attributes this to the Holy Spirit, as if it were His proper prerogative? Is it that, because Christ spoke only among the nation of the Jews, He does not appear to have reproved the world, inasmuch as one may be understood to be reproved who actually hears the reprover; while the Holy Spirit, who was in His disciples when scattered throughout the whole world, is to be understood as having reproved not one nation, but the world? For mark what He said to them when about to ascend into heaven: “It is not for you to know the times or the moments, which the Father has put in His own power. But you shall receive the power of the Holy Spirit, that comes upon you: and you shall be witnesses unto me in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth.” Surely this is to reprove the world. But would any one venture to say that the Holy Spirit reproves the world through the disciples of Christ, and that Christ Himself does not, when the apostle exclaims, “Would ye receive a proof of Him that speaks in me, namely Christ?” And so those, surely, whom the Holy Spirit reproves, Christ reproves likewise. But in my opinion, because there was to be shed abroad in their hearts by the Holy Spirit that love which casts out the fear, that might have hindered them from venturing to reprove the world which bristled with persecutions, therefore it was that He said, “He shall reprove the world:” as if He would have said, He shall shed abroad love in your hearts, and, having your fear thereby expelled, you shall have freedom to reprove. We have frequently said, however, that the operations of the Trinity are inseparable; but the Persons needed to be set forth one by one, that not only without separating Them, but also without confounding Them together, we may have a right understanding both of Their Unity and Trinity.
2. He next explains what He has said “of sin, and of righteousness, and of judgment.” “Of sin indeed,” He says, “because they have believed not on me.” For this sin, as if it were the only one, He has put before the others; because with the continuance of this one, all others are retained, and in the removal of this, the others are remitted. “But of righteousness,” He adds, “because I go to the Father, and you shall see me no more.” And here we have to consider in the first place, if any one is rightly reproved of sin, how he may also be rightly reproved of righteousness. For if a sinner ought to be reproved just because he is a sinner, will any one imagine that a righteous man is also to be reproved because he is righteous? Surely not. For if at any time a righteous man also is reproved, he is rightly reproved on this account, that, according to Scripture, “There is not a just man upon earth, that does good, and sins not.” And accordingly, when a righteous man is reproved, he is reproved of sin, and not of righteousness. Since in that divine utterance also, where we read, “Be not made righteous over-much,” there is notice taken, not of the righteousness of the wise man, but of the pride of the presumptuous. The man, therefore, that becomes “righteous over-much,” by that very excess becomes unrighteous. For he makes himself righteous over-much who says that he has no sin, or who imagines that he is made righteous, not by the grace of God, but by the sufficiency of his own will: nor is he righteous through living righteously, but is rather self-inflated with the imagination of being what he is not. By what means, then, is the world to be reproved of righteousness, if not by the righteousness of believers? Accordingly, it is convinced of sin, because it believes not on Christ; and it is convinced of the righteousness of those who do believe. For the very comparison with believers is itself a reproving of unbelievers. And this the exposition itself sufficiently indicates. For in wishing to open up what He has said, He adds, “Of righteousness, because I go to the Father, and you shall see me no more.” He does not say, And they shall see me no more; that is, those of whom He had said, “because they have believed not on me.” Of them He spoke, when expounding what He denominated sin, in the words, “because they have believed not on me;” but when expounding what He called righteousness, whereof the world is convicted, He turned to those to whom He was speaking, and said, “because I go to the Father, and you shall see me no more.” Wherefore it is of its own sins, but of others' righteousness, that the world is convicted, just as darkness is reproved by the light: “For all things,” says the apostle, “that are reproved, are made manifest by the light.” For the magnitude of the evil chargeable on those who do not believe, may be made apparent not only by itself, but also by the goodness of those who do believe. And since the cry of unbelievers usually is, How can we believe what we do not see? So the righteousness of unbelievers just required this very definition, “Because I go to the Father, and you shall see me no more.” For blessed are they who see not, and yet do believe. For of those also who saw Christ, the faith in Him that met with commendation was not that they believed what they saw, namely, the Son of man; but that they believed what they did not see, namely, the Son of God. But after His servant-form was itself also withdrawn from their view, then in every respect was the word truly fulfilled, “The just lives by faith.” For “faith,” according to the definition in the Epistle to the Hebrews, “is the confidence of those that hope, the conviction of things that are not seen.”
Source: Tractates on the Gospel of John (New Advent)