During the time of Jesus, the Sanhedrin ruled the religious life in Israel. It was a council of seventy members. They consisted of Sadducees, Pharisees, chief priests, and elders. One of the chief priests was the high priest who presided.
One of the members of the Sanhedrin was Nicodemus. For the Fourth Evangelist tells us, “Now there was a man of the Pharisees named Nicodemus, a ruler of the Jews” (John 3.1 ESV). The last phrase likely indicates that Nicodemus was also a member of the Sanhedrin. The Evangelist tells us that Nicodemus came to see Jesus. It was probably because of his status as a member of the Sanhedrin that he did so at night to avoid criticism from other Sanhedrin members (v. 2). Nicodemus said to Jesus, “Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do unless God is with him” (v. 3).
Several things can be gleaned from this positive statement by Nicodemus about Jesus. First, Nicodemus recognized Jesus as a true rabbi, thus not a false a teacher as most Sanhedrin members eventually regarded him. Second, Nicodemus believed that Jesus did genuine “signs from heaven” as Jews would say, meaning from God. Third, Nicodemus saying of Jesus that “God is with him” further affirms what he said before, that Jesus has “come from God.” This language echoes in reverse the second phrase of the Evangelist’s one sentence mini-prologue–“the Word was with God” (John 1.1b).
Then Jesus declared to Nicodemus what has been the foremost gospel saying of Jesus for so many Christians, especially modern Evangelicals, “Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God” (John 3.3). The word in the Greek text here translated “born again” is anothen, and it can also mean “born from above.” Many Christians have thought that Jesus had introduced a new concept by telling Nicodemus he needed to be born again. Jews commonly believed that being a physical descendant of Abraham through the promised seed Isaac made a person a member of God’s household if that person endeavored to keep the Torah (Law of Moses) and the men were circumcised in flesh as a sign of Israel’s covenant with God.
Nicodemus responded to Jesus in perplexity by saying, “How can a man be born when he is old?” (v. 4). He thus becomes one of so many characters in the Gospel of John (also in the synoptics, just not as much) who misunderstand Jesus by thinking he was speaking literally when he was really speaking figuratively. Jesus then went on to explain what he meant, comparing this new, spiritual birth with the blowing of the wind (vv. 5-8). He concludes, “So it is with everyone who is born of the Spirit,” referring to the Spirit of God (v. 8).
Nicodemus was surprised because he said, “How can these things be?” (v. 9). He said that because, as we next learn, he thought he knew the scriptures very well. We read, “Jesus answered, ‘Are you the teacher of Israel and yet you do not understand these things?'” (v. 10). Jesus’ description of Nicodemus as being “the teacher of Israel” (Greek text has the article) indicates that he must have been a leading Torah teacher even though this cannot be corroborated from any other ancient Jewish literature. Jesus said that because he implied that if a man has such status, he should know about being born again in the Jewish Bible (Old Testament). But how can Jesus expect that of Nicodemus since there is nothing in the Jewish Bible about being born again?
Then Jeremiah tells us that at the inbreaking of the blessed world-to-come, God will fully accomplish what he has been calling his people to do through the ages, of circumcising their hearts and thus being made new in spirit. We read, “Behold, the days are coming declares the LORD, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant that I made with their fathers on the day when I took them out of the land of Egypt, my covenant that they broke, though I was their husband, declares the LORD. But this is the covenant that I will make with the house of Israel after those days, declares the LORD: I will put my laws within them, and I will write it on their hearts. And I will be their God, and they shall be my people” (Jeremiah 31.31-33).
Those of us who are Gentile believers in Jesus inherit these promises as well. Thus, we all, both Jewish and Gentile believers, will be completely circumcised in heart. It will happen on “the last day,” at the resurrection of the just and the translation of the living saints. But to be counted in that blessed number, this process of spiritual regeneration must begin in this life, of being born again as Jesus proclaimed. How does it happen since the time of Jesus and thereafter? Jesus told Nicodemus how. He said, “And as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life” (John 3.15). As here, Jesus often called himself “the Son of Man.” He here meant his being lifted up on the cross just as Moses had made a bronze image of a snake, lifted it up on his staff, told the people bitten by the poisonous snakes to look at it, and they would be healed (Numbers 21.8-9). So, by truly believing in Jesus dying on the cross for our sins, and thus accepting him as our Savior, we have the promise of eternal life in the eschaton–the blessed world-to-come.