Ridderbos:

Verses 14 and 15 speak with increasing clarity about the way this descent and ascent of the Son of man, as well as the salvation represented in those events, is effected. Vs. 14 does so by comparing the raising up of the Son of man with that of the serpent in the wilderness. The reference is to the story in Nu. 21 :8f., where Moses raised a serpent up on a pole as a visible sign of salvation for all who thought they were about to die. Jesus speaks of the exaltation of the Son of man, so “lifted up” acquires a double meaning here (as also in 8:28; 12:32, 34): the exaltation of the Son of man (= his glorification) is effected by his being raised up on a cross. The comparison brings this last meaning to the fore as tertium comparationis, since the element of glorification cannot be applied to the serpent. In this connection the redemption-historical “necessity” (“must be”) of this being “lifted up” is important, strongly reminiscent as it is of passages like Mt. 16:21; Lk. 9:22 in which the humiliation of the Son of man is described as the way of his exaltation and is related to God’s counsel of salvation. Still–and this is typical for the Fourth Gospel–the crucifixion is not presented as Jesus’ humiliation but as the exaltation of the Son of man. The reason, obviously, is that Jesus’ suffering and death were the way in which he would return to God and be glorified by him and that in that way he would grant eternal life to those who believed in him (vs. 15). This last point again ties in clearly with Numbers 21: Just as gazing at the serpent was the God-given means of life, a sign both of God’s will to save and of his power over death, so Jesus as the Son of man in his suffering and death on the cross also embodies God’s will to save and power over death. But it “had to” happen in the way of the descent from heaven, of the incarnation of the Word, of his suffering and dying on the cross. Later, therefore, the living bread that came down from heaven and that “the Son of man will give” (6:27) will also be called his “flesh” that he gives for the life of the world, and only those who “eat the flesh of the Son of man and drink his blood” will have life in themselves (6:51,53).

But all this is not further explicated, at least not in vss. 14 and 15. Here the reference is to “whoever believes in him.” 107 The object of this faith is the Son of man as the crucified one as well as the crucified Son of man. The Son of man “must” go this way, which is inconceivable to the flesh. But he takes it as one destined by God to the highest glory, as one who enters death in order thus, like the serpent lifted up by Moses, to be the great sign that in him God has the will and the capacity to save from destruction everyone who believes. Faith receives its character from the one as well as from the other truth. It is faith in the powerful Messiah-King promised by God, the Son of man, but in him as the crucified one; it is faith in the power of him who is powerless in the flesh and in the eyes of the flesh. Therein, also, lies the difference from “belief in his name” (2:23), which rests exclusively on the manifestation of Jesus’ power and which by itself need be no more than a conclusion of which the “flesh” is capable. But to be able to see and to believe in the heaven descended, cross-exalted Son of man–that takes a different set of eyes, and for that one must be born from above.

Verse 16 reduces all this to its deepest underlying cause and to its ultimate simplicity with an explanatory statement: “For God so loved the world . . . . ” What Moses did at God’s instruction in the wilderness, lift up the serpent, was great and marvelous. But nowhere more clearly than here do we see the difference (described also in 1: 17) between what God gave through Moses and the grace and truth that came through Jesus Christ (cf. 6:32).

All the emphasis here lies on the “so”: “in this manner,” “in this measure.” This word refers back to the “how” of the lifting up of the Son of man, but it also directs the reader’s attention to the measure of God’s love that underlies that lifting up. All the terminology is attuned to the latter. Here we read not of the Son of man but of God’s only-begotten Son (cf. 1:18), so designated here as the highest gift God could give (cf. Ro. 8:32: “who did not spare his own Son”; Gn. 22:16). And we read “gave” in the sense of what is elsewhere called “giving up,” “surrendering” (e.g., Ro. 4:25; 8:32; Mk. 9:31), namely to death on the cross. All this shows how in the Fourth Gospel, as elsewhere in the New Testament, the God-given sacrifice of Christ is of central significance. This is surely the case also because in that surrender the glory of God manifested itself so clearly “in the flesh” of the man Jesus, but above all because it brought to its highest manifestation the measure of God’s love for the world (cf. 13: 1).

There is a close connection here with the utterance of John the Baptist in 1:29 (35): “Behold, the Lamb of God, who takes away the sin of the world!” That utterance includes no reflection on the death of Christ, and 3:16 does not mention in so many words the sin of the world as that which makes necessary God’s surrender of his Son. The common component in the two pronouncements is that it is God who makes the all-embracing sacrifice for the world. There is no further analysis of why God loves thus. The text’s exclusive concern is the fact and the magnitude of God’s love. It is love that not only manifests itself in God’s power over death, the death into which the world (like Israel in the wilderness) would sink; in the death of Christ it also identifies with the world in its lostness and thus imparts the deepest meaning to the great statement in the prologue, “and the Word became flesh.”

Again, as in vs. 15, we read : ” . . . that whoever believes in him (the Son) . . . ,” and again the essence of believing in his name becomes clear. The starting point of faith does not lie in the fact that the world returned to God in the ascent of the Son of man and so found its lost self, any more than the starting point of faith in the incarnation lies in the fact that in the man Jesus God again put the world on the track of true humanity (“not perish,” “have eternal life”). The starting point is that God in his eternal love returned to the world as to his own, that he loved it in the surrender of his only-begotten Son (cf. 3:35), and that the Father loves the Son because he gave his own life (cf. 10: 15) in a love that persisted to the end (cf. 13: Iff.). It is faith in a path that, before it ascended to the glory of heaven, first descended to the depth of the earth, that is not itself from below but from above as the sign of true sonship and of those who are born of God (cf. 1: 12f.).

17-18 If thus, as the content of the heavenly things, vss. 13-16 refer above all to the great salvation-historical (“eschatological”) events effected in the mission of Jesus as the Son of God, the consequence for humanity and the world is an all-determining final decision. Already vss. 15 and 16 mentioned ” eternal life” twice as the presently inaugurated gift for one who believes (and thus “has” eternal life).11O Vss. 17ff. refer to the decisive “critical” character of the mission of the Son of God. In close connection with vs. 16, but now per negationem, the divine will to save that is manifest in this mission is again confirmed, and any notion that the Father sent the Son into the world to judge the world is banished. The idea in itself is not foreign: throughout prophecy the coming of the kingdom of God is accompanied by the judgment of God over his enemies (cf. also Mt. 3:7f. par.), and judgment is part of the fullness of the divine powers of the Son of man (cf. 5:22, 27; Mt. 25:31ff.). But in the present passage everything is viewed from the perspective of the mission of the Son and the descent of the Son of man from heaven. And that mission and descent have no other purpose, as the Evangelist keeps saying (cf. 12:47; 8: IS), than to open a way, in him, for faith and for the world’s salvation.

This is not (vs. 18) to delay the decision; on the contrary, it is to bring it closer. For he who descended is God’s only-begotten Son, and God has put “all things into his hand” (vs. 35). For that reason the Son has the power even now to release people from their guilt (“authority on earth to forgive sins,” Mt. 9:6), and one who believes in him does not come under judgment. In the fellowship of faith with him judgment is suspended. And conversely, one who does not believe in him is already under judgment. The judgment to come in the confrontation with the coming judge of the world has become for that person an issue of great present relevance. The perfect tense (“are condemned”) refers to the situation in which that person has placed himself or herself, not on account of the verdict already pronounced by the Son, but “because he (or she) has not believed in the name of the only Son of God.” That person has not acknowledged the saving love of God manifest in his Son; and that does not only mean not to know God’s love but to live under the doom of its absence, the privatio actuosa. Still for that person, too, the truth is that the coming of the Son is not aimed at condemnation. That person still has to deal, not with the judge of the world in his heavenly glory, but with the Son who has descended into the world and who continues to woo people with the love of God, yet even now with no other purpose than to save the world, even those in the world who do not believe in him (cf. 5:34).

A striking feature of this passage, finally, is the degree to which everything is concentrated on the importance of believing. Whereas in vss. 1-8 the birth from above is posed above all else as the indispensable condition for entry into the kingdom of God, in vs. 12 and especially in vss. 15ff. the crucial importance of believing comes increasingly to the fore. It is clear that the one cannot do without the other: the birth from above, however much it is a miracle of the Spirit, is not effected without the call to faith and the response of faith. Nor is faith simply a stage in the salvation-order transformation of a person; it rather describes the totality of transformation as the work of the Spirit. And in this connection faith is always the way in which and the means by which the new life comes into being. It is for this reason that all the emphasis falls on believing.

On the other hand, it is no less true that the new birth does not rest on an antecedent human decision. Faith is not the response of the higher or the better self to the message of the gospel. Nor is it an enlivening in the prisonhouse of the flesh by a voice in which a person recognizes himself in his divine origin, his deepest “disposition,” his “authentic existence,” or the like, for as we read in 5 :25: “The hour is coming, and now is, when the dead will hear the voice of the Son of God, and those who hear will live” (cf. vs. 24). In other words, faith belongs to the ministry and miracle of the Spirit. It is not a predisposition that is already present but a decision that is realized in the address of the Word and that is subject to the moral power that proceeds from that Word. There can be a “hearing” and a “seeing” only when the Word is understood and followed in accordance with its meaning (cf. 5:25; 6:26).

In this connection much has been, and is being, written about the Johannine idea of predestination, and the reference to texts like 6:37, 39, 44; 10:29; 17:2ff. is self-evident. And, in contrast, when it comes to faith or the call to faith the Evangelist obviously does not think of a preestablished divine decision, for his entire Gospel is a continuing struggle on behalf of faith and a continual indictment of the culpable and mysterious character of unbelief. Especially in the dialogue with Nicodemus, where the necessity of birth from above is so clearly asserted, not believing and not accepting (vss. 12, 13, 18ff.) are not attributed to the flesh, and the situation of Nicodemus himself is viewed not as closed but as clearly kept open. The Spirit is like the wind, blowing where it wills. Hence one must inevitably conclude that every deterministic schematism is as alien to the gospel as is any dogma of inviolable human freedom. faith will always bear on its face the sign of the grace of being a child of God, just as unbelief bears the sign of disobedience to the summons of the gospel (cf. vs. 36; see also the comments on 1:12f.).

Herman N. Ridderbos, The Gospel According to John: A Theological Commentary, trans., John Vriend (Grand Rapids, Mich.: W.B. Eerdmans, 1997), 136-141. [Footnotes not included; italics original; and underlining mine.]