Herewith comments from Calvin on John 3:33-4: “Whoever receives his testimony sets his seal to this, that God is true. For he whom God has sent utters the words of God, for he gives the Spirit without measure.”
First, on v. 33: for there to be faith–that is, for there to be a “church” at all–God must first have spoken. As we have seen previously, God always acts first and speaks into existence whatever comes to be. This truth is no less true when applied to ecclesiology than to the creation of the world. For this reason, the Word always precedes the church, stands above her, and is the source of the air that she breathes. If the Word should be taken away, she would be caught forthwith in the throes of asphyxiation. 1 And as on the corporate level, so also on the individual level: faith is an ex post facto reality that presupposes the viva vox Dei.
“Faith” therefore “correspond[s] to the truth of God,” and to nothing else. It is a thing utterly different from trust in any opinions whatsoever, however pious they may be. It is God, not man, who cannot lie, and it is only by adherence to the Word of God in the Gospel that faith has any meaning. This is to say that faith takes its character from its object: it is not due to a special vigor of subjective belief that faith is steadfast, but because God himself “is free from all doubt.” God gets the victory over Satan, and for that reason–and only that reason–faith gets the victory over Satan.
But he who receiveth his testimony. Here he exhorts and encourages the godly to embrace boldly the doctrine of the Gospel, as if he had said that there was no reason why they should be ashamed or uneasy on account of their small number, since they have God as the Author of their faith, who alone abundantly supplies to us the place of all the rest. And, therefore, though the whole world should refuse or withhold faith in the Gospel, this ought not to prevent good men from giving their assent to God. They have something on which they may safely rest, when they know that to believe the Gospel is nothing else than to assent to the truths which God has revealed. Meanwhile, we learn that it is peculiar to faith to rely on God, and to be confirmed by his words; for there can be no assent, unless God have, first of all, come forward and spoken. By this doctrine faith is not only distinguished from all human inventions, but likewise from doubtful and wavering opinions; for it must correspond to the truth of God, which is free from all doubt, and therefore, as God cannot lie, it would be absurd that faith should waver. Fortified by this defense, whatever contrivances Satan may employ in his attempts to disturb and shake us, we shall always remain victorious.
Hence, too, we are reminded how acceptable and precious a sacrifice in the sight of God faith is. As nothing is more dear to him than his truth, so we cannot render to him more acceptable worship than when we acknowledge by our faith that He is true, for then we ascribe that honor which truly belongs to him. On the other hand, we cannot offer to him a greater insult than not to believe the Gospel; for he cannot be deprived of his truth without taking away all his glory and majesty. His truth is in some sort closely linked with the Gospel, and it is his will that there it should be recognized. Unbelievers, therefore, as far as lies in their power, leave to God nothing whatever; not that their wickedness overthrows the faithfulness of God, but because they do not hesitate to charge God with falsehood. If we are not harder than stones, this lofty title by which faith is adorned ought to kindle in our minds the most ardent love of it; for how great is the honor which God confers on poor worthless men, when they, who by nature are nothing else than falsehood and vanity, are thought worthy of attesting by their signature the sacred truth of God?
Next, on v. 34: Calvin (following Augustine, as he says) applies the giving of the Spirit to Christ rather than to ordinary men. While ordinary men have need of each other, a fact that thus necessitates “the mutual bond of brotherly intercourse between us,” Christ receives the Spirit in “unlimited abundance.” The Spirit “dwell[s] without measure” in him, and from his fullness we receive whatever graces we have.
The meaning is now plain, that the Spirit was not given to Christ by measure, as if the power of grace which he possesses were in any way limited; as Paul teaches that
to every one is given according to the measure of the gift,
so that there is no one who alone has full abundance. For while this is the mutual bond of brotherly intercourse between us, that no man separately considered has every thing that he needs, but all require the aid of each other, Christ differs from us in this respect, that the Father has poured out upon him an unlimited abundance of his Spirit. And, certainly, it is proper that the Spirit should dwell without measure in him, that we may all draw out of his fullness, as we have seen in the first chapter. And to this relates what immediately follows, that the Father hath given all things into his hand; for by these words John the Baptist not only declares the excellence of Christ, but, at the same time, points out the end and use of the riches with which he is endued; namely, that Christ, having been appointed by the Father to be the administrator, he distributes to every one as he chooses, and as he finds to be necessary; as Paul explains more fully in the fourth chapter of the Epistle to the Ephesians, which I lately quoted. Although God enriches his own people in a variety of ways, this is peculiar to Christ alone, that he has all things in his hand.