"There was among the Pharisees a man named Nicodemus, a ruler of the Jews. He came to Jesus by night and said to him : "Rabbi, we know that you are a teacher from God ; for no man can do these miracles that you do, unless God is with him." John 3. 1, 2
In the great crowd that invaded Jerusalem on the occasion of the Passover feast, many people had to face the obvious : the miracles performed by Jesus showed that he was someone extraordinary (John 2: 2). 23-25). But few understood that these miracles were intended to prove his divinity and to accredit his message.
This is not the case of Nicodemus ; he perfectly understands that Jesus has the approval of God. He wants to benefit from his teaching. In order not to compromise his social and religious position or to be able to spend more time with Jesus, he comes to him by night. But his approach is that of someone who seeks the truth without limiting himself to what he already knows or the reassuring opinion of everyone.
What revelations the Lord brings him! The necessity of the new birth, the Spirit that produces it, the Son of man raised on the cross who saves him who believes in him, the love of God who gives his Son.
Nicodemus could not immediately understand the full extent of these revelations. He had to think about it and they convinced him enough, because later he had the courage to try to defend Jesus before the leaders, Pharisees like him, who wanted to kill him (John 7. 50-52) . It is an act of courage that God appreciates since he took care to record it in the Bible.
We find Nicodemus after the crucifixion of the Lord. This was made at the instigation of the leaders of the Jewish people, his peers ; yet he is not ashamed to join Joseph of Arimathea to take care of the body of Jesus. It is he who brings a mixture of myrrh and aloe, of considerable value, to embalm the body of the Lord. The Word then recalls that Nicodemus "in the beginning went to Jesus by night" (John 19:39), as if to emphasize the importance of this initial step and the transformation that had taken place in him.
It was on this occasion that Jesus had given Nicodemus the central word of the Gospel : "God so loved the world that he gave his only begotten Son, that whosoever believeth in him should not perish, but that he have eternal life" (John 3:16).
Source (Pleasing the Lord)