Chapter 3 of John is rich in images and messages from God to us. The “Born again Christians” motif comes from verse 3, for example (sadly now used as much politically as religiously). But if we reread verses 1-2, we should notice that Jesus did not respond to the statements by Nicodemus, saying instead he needed a new birth. Jesus respected Nicodemus so went directly to the reason Nicodemus was there. Basically, Nicodemus had the same question as the rich man, ‘What must I do?’
He goes on to say, no one can enter the kingdom of God unless they are born of water and the Spirit. NIV Baptism is a Jewish practice, so Nicodemus understood that idea; he was not sure about the idea that it would lead to a new life. The addition of being born in the spirit is also a Jewish concept, and again Nicodemus had to think of it in the context of new birth.
Jesus uses a play on words when he speaks of the wind and the spirit because the same Hebrew word is used for both, also the same Greek word. In the Old Testament, wind is applied in the sense of the Holy Spirit. Nicodemus knew that; he had to work on the idea of becoming like the Spirit.
As an aside, in this private conversation at night, Jesus in verses 11-13 clearly stated that he came from Heaven, but he never claimed to be God. No one has ever been up to Heaven except the Son of Man who came down from Heaven. Phillips
The next verse ties John to the passage from Numbers. The Son of Man must be lifted above the heads of men—as Moses lifted up that serpent in the desert—so that any man who believes in him may have eternal life. Phillips To be clear, Jesus calls himself the Son of Man. He says the Son of Man came directly from Heaven. And he says that the Son of Man will be like the serpent of Moses.
That means we need to understand what happened in the desert. God was in the process of saving the people from slavery when they began to turn against God because of the food service. Turning away from God is to turn toward death; those complainers died. When the people repented, God instructed Moses to make a bronze snake. When the people looked at the snake, they would be saved from death.
There is a great deal going on in the passage, but it is worth considering why God chose a snake to save the people in that instance. The traditional Jewish understanding is that the people were, in looking up, actually looking to Heaven.
That is in keeping with the well-known (almost hackneyed) words of Jesus: For God so loved the world that he gave his only and unique Son, so that everyone who trusts in him may have eternal life, instead of being utterly destroyed. CJB By holding up the cross as Moses held the serpent, we look to it for our safety and life.
As Paul put it: But God is so rich in mercy and loves us with such intense love that, even when we were dead because of our acts of disobedience, he brought us to life along with the Messiah — it is by grace that you have been delivered. CJB Thus the serpent. Nothing Moses or the people did saved them. Neither did the serpent. Moses would have tacked an old, smelly sandal on the staff, and if God wanted to, His Grace would have worked just as well.
There is nothing I can do to save myself. I can only hope for the Mercy of God to rescue me.
Be righteous and do good.