Nicodemus was a member of the Sanhedrin, the highest legal authority among the Jews at that time and we find in verse 2 that he came to talk to Jesus by night. Now this does not necessarily mean that he was visiting Jesus in secret, indeed in John 7:50 he defended Jesus in front of the High Priests and the Pharisees. He also helps in Jesus’ burial in John 19:39.
He may well have been visiting by night in order to avoid the crowds so he could speak in private to Jesus, who, Nicodemus acknowledged, was sent from God.
Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. (John 3:3)
Verily (αμην, amen in the Greek) is a sign of strong emphasis on the statement, signifying it’s importance. Jesus is speaking here of the spiritual rebirth of a new Christian (see 2 Cor 5:17). However Nicodemus misses the spiritual meaning of Jesus’ statement.
Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. (John 3:5)
The water baptism was used by the Jews for Gentile converts to Judaism and was used by John the Baptist as a sign of repentance. Being born of water and the Spirit signifies the repentance of a believer and the new life of a Christian through the Holy Spirit. The water is a symbol of the cleansing work of the Holy Spirit and is not sufficient by itself (Matthew 3:11).
The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit. (John 3:8)
We must not reject the idea because we don’t see or understand it. We can’t see the baptism of the Holy Spirit but we know it is there because of the resulting work in a believer (Romans 8:16).
Nicodemus didn’t understand it completely and hence was unwilling to accept the idea. However, the idea of recreation and renewal is not new or just in the New Testament (Psalms 51:10 and Ezekiel 11:19, 36:26). Nicodemus, being a Pharisee and a member of the Sanhedran, should have understood the concept.
Remember not to mix up the regenerating work of the Holy Spirit and being born again! Being born of the Spirit is a one time thing, you aren’t constantly being born! You are a new creation through being born again.
Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen; and ye receive not our witness. (John 3:11)
Nicodemus accepts that Jesus is from God yet he does not accept Jesus’s witness. Note that Jesus is using the plural we, suggesting that he is including his disciples in this statement. Also the Greek for ‘you’ in this case in plural as well, meaning that Jesus is not just refering to Nicodemus here.
And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven. (John 3:13)
After refering to heavenly things in verse 12, Jesus is saying here that the no man has gone to heaven and back, and therefore only the Son of Man is qualified to speak of heavenly things. An interesting point is that the words “which is in heaven” is in the present tense, signifying the omnipresence nature of the Son of Man who is Jesus and confirming his deity.
The next few verses draw a parallel between events in Numbers 21 and also references Jesus’ coming death. The main points of this is of a situation where man is doomed without a cure, hence man must look to the Son of Man to be saved. The explanation for why the Son of Man should be lifted up is one of the most well-known verses in the Bible.
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (John 3:16)
This verse explains why the Son of man should be lifted up, because God loves us so much he has sent Jesus to die so that we should not perish but have everlasting life.
Man is already guilty through the law and therefore needs saving and this is the reason that Jesus came, not to pronounce condemnation but to die for us.
He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. (John 3:18)
This is why Jesus didn’t come to condemn, we are condemned already if we do not believe in the Son of God because that belief is the only thing that can save us from perishing (Romans 8:1).
And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. (John 3:19)
This is why man is condemned, because men love darkness rather than light, because man’s deeds are evil. The term ‘Light’ is used here to denote Jesus, the light of the world and man is condemned by rejecting this light.
Evil people hate the Light because the light shows their sin. The opposite is true of those who do good, they come to the Light because they are of God.
But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. (1 John 1:7)