“Now there was a Pharisee, a man named Nicodemus who was a member of the Jewish ruling council. He came to Jesus at night and said, “Rabbi, we know that you are a teacher who has come from God. For no one could perform the signs you are doing if God were not with him.’”
– John 3:1-2
Nicodemus was a Pharisee and a member of the Jewish Sanhedrin, the highest ruling council among the Jews. Many of the Pharisees accompanied Jesus as he toured the cities, acting as spies and posing questions in an attempt to trip him up so they could find some cause to arrest him. Nicodemus was one of those followers, but he was not one of the spies. He came to believe in Jesus, and so when he approached him this night, he came in his own right, not as an official delegate of the Sanhedrin. In fact, this evening’s visit was in secret. He wanted to know more without being seen by the multitudes. Jesus, perceiving that Nicodemus came to inquire about the Kingdom, told him:
“Jesus replied, “Very truly I tell you, no one can see the kingdom of God unless they are born again.” “How can someone be born when they are old?” Nicodemus asked. “Surely they cannot enter a second time into their mother’s womb to be born!” Jesus answered, “Very truly I tell you, no one can enter the kingdom of God unless they are born of water and the Spirit. Flesh gives birth to flesh, but the Spirit gives birth to spirit. You should not be surprised at my saying, ‘You must be born again.’ The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit.’”
– John 3:3-8
Jesus was laying the groundwork for entrance into the kingdom. By saying “What has been born from flesh is flesh,” Jesus was not talking about fleshly birth, or returning to a woman’s womb. As a Pharisee, Nicodemus was no doubt righteous in works and faithful in keeping the law. But Jesus was showing that even the best of the flesh cannot enter the kingdom on that ground alone.
And when he says that you may hear the sound of wind but not know from where it is coming, he means that being born from the spirit is not discernible by the eye. You can see the affect of the wind, but not the wind itself. Likewise, with your fleshly eyes, you may be able behold the manifestation of the spirit, but you cannot actually discern the spirit itself. Since the re-birth is not accomplished by fleshly actions, and it is not discernable to the eye, Nicodemus was still baffled.
“How can this be?” Nicodemus asked. “You are Israel’s teacher,” said Jesus, “and do you not understand these things? Very truly I tell you, we speak of what we know, and we testify to what we have seen, but still you people do not accept our testimony. I have spoken to you of earthly things and you do not believe; how then will you believe if I speak of heavenly things?”
– John 3:9-12