The following article is excerpted from the International Standard Bible Encyclopedia, which is in the public domain.
A Pharisee and a "ruler of the Jews," mentioned only by John. He (1) interviewed Christ at Jerusalem and was taught by Him the doctrine of the New Birth (John 3:1-15) (2) defended Him before the Sanhedrin (John 7:50-52), and (3) assisted at His burial (John 19:39-42).
The InterviewThis meeting, which it has been surmised took place in the house of John (John 3:1-15), was one of the results of our Lord's ministry at Jerusalem during the first Passover (compare John 3:2 with John 2:23). Although Nicodemus had been thus won to believe in the divine nature of Christ's mission, his faith was yet very incomplete in that he believed Him to be inspired only after the fashion of the Old Testament prophets. To this faint-hearted faith corresponded his timidity of action, which displayed itself in his coming "by night," lest he should offend his colleagues in the Sanhedrin and the other hostile Jews (John 3:2). In answer to the veiled question which the words of Nicodemus implied, and to convince him of the inadequacy of mere intellectual belief, Christ proclaimed to him the necessity for a spiritual regeneration:
"Except one be born anew, he cannot see the kingdom of God" (John 3:3). This was interpreted by Nicodemus only in its materialistic sense, and therefore caused him bewilderment and confusion (John 3:4). But Christ, as on another occasion when dealing with His questioners on a similar point of doctrine (compare John 6:52,53), answered his perplexity only by repeating His previous statement (John 3:5). He then proceeded to give further explanation. The re-birth is not outward but inward, it is not of the body but of the soul (John 3:6). Just as God is the real agent in the birth of the body, so also is He the Creator of the New Spirit; and just as no one knoweth whence cometh the wind, or "whither it goeth," yet all can feel its effects who come under its influence, so is it with the rebirth. Only those who have experienced it as a change in themselves, wrought by the Divine Power, are qualified to judge either of its reality or of its effects (John 3:7,8).
But Nicodemus, since such experience had not yet been his, remained still unenlightened (John 3:9). Christ therefore condemned such blindness in one who yet professed to be a teacher of spiritual things (John 3:10), and emphasized the reality in His own life of those truths which He had been expounding (John 3:11). With this, Christ returned to the problem underlying the first statement of Nicodemus. If Nicodemus cannot believe in "earthly things," i.e. in the New Birth, which, though coming from above, is yet realized in this world, how can he hope to understand "heavenly things," i.e. the deeper mysteries of God's purpose in sending Christ into the world (John 3:12), of Christ's Divine sonship (John 3:13), of His relationship to the atonement and the salvation of man (John 3:14), and of how a living acceptance of and feeding upon Him is in itself Divine life (John 3:15; compare John 6:25-65)?
The DefenseThe above interview, though apparently fruitless at the time, was not without its effect upon Nicodemus. At the Feast of Tabernacles, when the Sanhedrin was enraged at Christ's proclamation of Himself as the "living water" (John 7:37,38), Nicodemus was emboldened to stand up in His defense. Yet here also he showed his natural timidity. He made no personal testimony of his faith in Christ, but sought rather to defend Him on a point of Jewish law (John 7:50-52; compare Exodus 23:1; Deuteronomy 1:16,17; 17:6; 19:15).
The BurialBy this open act of reverence Nicodemus at last made public profession of his being of the following of Christ. His wealth enabled him to provide the "mixture of myrrh and aloes, about a hundred pounds," with which the body of Jesus was embalmed (John 19:39).
The Gospel of Nicodemus and other apocryphal works narrate that Nicodemus gave evidence in favor of Christ at the trial before Pilate, that he was deprived of office and banished from Jerusalem by the hostile Jews, and that he was baptized by Peter and John. His remains were said to have been found in a common grave along with those of Gamaliel and Stephen.
Nicodemus is a type of the "well-instructed and thoughtful Jew who looked for the consummation of national hope to follow in the line along which he had himself gone, as being a continuation and not a new beginning" (Westcott). The manner in which the Gospel narrative traces the overcoming of his natural timidity and reluctant faith is in itself a beautiful illustration of the working of the Spirit, of how belief in the Son of Man is in truth a new birth, and the entrance into eternal life.
International Standard Bible Encyclopedia