But there was a man (chap. 3)-and that a Pharisee-who was not satisfied with this inoperative conviction. His conscience was reached. Seeing Jesus, and hearing His testimony, had produced a sense of need in his heart. It is not the knowledge of grace, but it is with respect to man's condition a total change. He knows nothing of the truth, but he has seen that it is in Jesus, and he desires it. He has also at once an instinctive sense that the world will be against him; and he comes by night. The heart fears the world as soon as it has to do with God; for the world is opposed to Him. The friendship of the world is enmity against God. This sense of need made the difference in the case of Nicodemus. He had been convinced like the others. Accordingly he says, "We know that thou art a teacher come from God." And the source of this conviction was the miracles. But Jesus stops him short; and that on account of the true need felt in the heart of Nicodemus. The work of blessing was not to be wrought by teaching the old man. Man needed to be renewed in the source of his nature, without which he could not see the kingdom. 
The things of God are spiritually discerned; and man is carnal, he has not the Spirit. The Lord does not go beyond the kingdom-which, moreover, was not the law-for Nicodemus ought to have known something about the kingdom. But He does not begin to teach the Jews as a prophet under the law. He presents the kingdom itself; but to see it, according to His testimony, a man must be born again. But the kingdom as thus come in the carpenter's Son could not be seen without a wholly new nature, it struck no chord of man's comprehension or Jews' expectation, though testimony to it was amply given in word and work: as to entering and having a part in it there is more development as to the how. Nicodemus sees no farther than the flesh.
The Lord explains Himself. Two things were necessary-to be born of water, and of the Spirit. Water cleanses. And, spiritually, in his affections, heart, conscience, thoughts, actions, etc., man lives, and in practice is morally purified, through the application, by the power of the Spirit, of the word of God, which judges all things, and works in us livingly new thoughts and affections. This is the water; it is withal the death of the flesh. The true water which cleanses in a christian way came forth from the side of a dead Christ. He came by water and blood, in the power of cleansing and of expiation. He sanctifies the assembly by cleansing it through the washing of water by the word. "Ye are clean through the word which I have spoken unto you." It is therefore the mighty word of God which, since man must be born again in the principle and source of his moral being, judges, as being death, all that is of the flesh. 
But there is in fact the communication of a new life; that which is born of the Spirit is spirit, is not flesh, has its nature from the Spirit. It is not the Spirit-that would be an incarnation; but this new life is spirit. It partakes of the nature of its origin. Without this, man cannot enter into the kingdom. But this is not all. If it was a necessity for the Jew, who already was nominally a child of the kingdom, for here we deal with what is essential and true, it was also asovereign act of God, and consequently it is accomplished wherever the Spirit acts in this power. "So is every one that is born of the Spirit." This in principle opens the door to the Gentiles.
Nevertheless Nicodemus, as a master of Israel, ought to have understood this. The prophets had declared that Israel was to undergo this change, in order to enjoy the fulfilment of the promises (see Ezek. 36), which God had given them with regard to their blessing in the holy land. But Jesus spoke of these things in an immediate way, and in connection with the nature and the glory of God Himself. A master in Israel ought to have known that which the sure word of prophecy contained. The Son of God declared that which He knew, and that which He had seen with His Father. The defiled nature of man could not be in relationship with Him who revealed Himself in heaven whence Jesus came. The glory (from the fulness of which He came, and which formed therefore the subject of His testimony as having seen it, and from which the kingdom had its origin) could have nothing in it that was defiled. They must be born again to possess it. He bore testimony therefore, as having come from above and knowing that which was suitable to God His Father. Man did not receive His testimony. Convinced outwardly by miracles he might be; but to receive that which was befitting the presence of God was another thing. And if Nicodemus could not receive the truth in its connection with the earthly part of the kingdom, of which even the prophets had spoken, what would he and the other Jews do if Jesus spoke of heavenly things? Nevertheless no one could learn anything about them by any other means. No one had gone up there and come down again to bring back word. Jesus only, in virtue of what He was, could reveal them-the Son of man on earth, existing at the same time in heaven, the manifestation to men of that which was heavenly, of God Himself in man-as God being in heaven and everywhere-as the Son of man being before the eyes of Nicodemus and of all. Nevertheless He was to be crucified, and thus lifted up from the world to which He had come as the manifestation of the love of God in all His ways and of God Himself, and so only could the door be opened for sinful men into heaven, so only a link formed for man with it.
For this brought out another fundamental truth. If heaven was in question, something more was needed than being born again. Sin existed. It must be put away for those who should have eternal life. And if Jesus, coming down from heaven, was come to impart this eternal life to others, He must, in undertaking this work, put sin away-be thus made sin-in order that the dishonour done to God should be washed away, and the truth of His character (without which there is nothing sure, or good, or righteous) maintained. The Son of man must be lifted up, even as the serpent was lifted up in the wilderness, that the curse, under which the people were dying, might be removed. His divine testimony rejected, man, as he was down here, shewed himself to be incapable of receiving blessing from above. He must be redeemed, his sin expiated and put away; he must be treated according to the reality of his condition, and according to the character of God who cannot deny Himself. Jesus in grace undertook to do this. It was necessary that the Son of man should be lifted up, rejected from the earth by man, accomplishing the atonement before the God of righteousness. In a word, Christ comes with the knowledge of what heaven is and divine glory. In order that man might share it, the Son of man must die-must take the place of expiation-outside the earth.  Observe here the deep and glorious character of that which Jesus brought with Him, of the revelation He made.
The cross, and the absolute separation between man on earth and God-this is the meeting-place of faith and God; for there is at once thetruth of man's condition, and the love that meets it. Thus, in approaching the holy place from the camp, the first thing they met on going through the gate of the court was the altar. It presented itself to every one that quitted the world without, and entered in. Christ, lifted up from the earth, draws all men to Him. But if (owing to man's state of alienation and guilt) it needed that the Son of man should be lifted up from the earth, in order that whosoever believes in Him should have everlasting life, there was another aspect of this same glorious fact; God had so loved the world that He had given His only begotten Son, that whosoever believes in Him should have everlasting life. On the cross we see the necessity morally of the death of the Son of man; we see the ineffable gift of the Son of God. These two truths unite in the common object of the gift of eternal life to all believers. And if it was to all believers, it was a question of man, of God, and of heaven, and went outside the promises made to the Jews, and the limits of God's dealings with that people. For God sent His Son into the world, not to condemn it, but to save it. But salvation is by faith; and he who believes in the coming of the Son, putting all things now to the test, is not condemned (his state is decided thereby); he who believes not is condemned already, he has not believed in the only begotten Son of God, he has manifested his condition.
And this is the thing that God lays to their charge. Light is come into the world, and they have loved darkness because their works were evil. Could there be a more just subject of condemnation? It was no question of their not finding pardon, but of their preferring darkness to light that they might continue in sin.
The rest of the chapter presents the contrast between the positions of John and of Christ. They are both before the eye. The one is the faithful friend of the Bridegroom, living only for Him; the other is the Bridegroom, to whom all belongs: the one, in himself, an earthly man, great as might be the gift he had received from heaven; the other from heaven Himself, and above all. The bride was His. The friend of the Bridegroom, hearing His voice, was full of joy. Nothing more beautiful than this expression of John the Baptist's heart, inspired by the Lord's presence, near enough to Jesus to be glad and rejoice that Jesus was all. Thus it ever is.
With respect to the testimony, John bore witness in connection with earthly things. For that end he was sent. He who Himself came from heaven was above all, and bore witness of heavenly things, of that which He had seen and heard. No one received His testimony. Man was not of heaven. Without grace one believes according to one's own thoughts. But in speaking as a man on the earth, Jesus spoke the words of God; and he who received His testimony set to his seal that God was true. For the Spirit is not given by measure. As a witness the testimony of Jesus was the testimony of God Himself; His words, the words of God. Precious truth! Moreover, He was the Son,  and the Father loved Him, and had given all things into His hand. This is another glorious title of Christ, another aspect of His glory. But the consequences of this for man were eternal. It was not almighty help to pilgrims, nor faithfulness to promises, so that His people could trust in Him in spite of all. It was the quickening life-giving Son of the Father. All was comprised in it. "He who believeth in the Son hath everlasting life, he who believeth not shall not see life." He remains in his guilt. The wrath of God abides on him.
All this is a kind of introduction. The ministry of the Lord, properly so called, comes after. John (v. 24) was not yet cast into prison. It was not till after that event that the Lord began His public testimony. The chapter we have been considering explains what His ministry was, the character in wh ich He came, His position, the glory of His Person, the character of the testimony He bore, the position of man in connection with the things of which He spake, beginning with the Jews, and going on, by the new birth, the cross, and the love of God, to His rights as come into the world, and the supreme dignity of His own Person, to His properly divine testimony, to His relationship with the Father, the object of whose love He was, and who had given all things into His hand. He was the faithful witness, and that of heavenly things (see chap. 3:13), but He was also the Son Himself come from the Father. Everything for man rested on faith in Him. The Lord comes out from Judaism, while presenting the testimony of the prophets, and brings from heaven the direct testimony of God and of glory, shewing the only ground on which we can have a part in it. Jew or Gentile must be born again; and heavenly things could only be entered by the cross, the wondrous proof of God's love to the world. John gives place to Him, bringing out-not in public testimony to Israel but to his disciples-the true glory of His Person and of His work  in this world. The thought of the bride and Bridegroom is, I believe, general. John says indeed that he is not the Christ, and that the earthly bride belongs to Jesus; but He has never taken her; and John speaks of His rights, which for us are realised in a better land and another clime than this world. It is, I repeat, the general idea. But we have now entered on the new ground of a new nature, the cross, and the world and God's love to it.