This part of the gospel is a familiar one: Jesus is talking with Nicodemus. Nicodemus (the name means “conqueror for the people”) was a Pharisee and is called a “ruler of the Jews” in John 3:1; which probably means that he was a member of the Sanhedrin. He visited Jesus at night and admitted His divine mission. Our reading today is part of Jesus’ discourse on baptism. Jesus has told Nicodemus that no one can see the kingdom of God unless he is born “again” (the word is anothen, which also means “from above”), a statement which confuses Nicodemus. This allows Jesus to explain the significance of His mission). To better understand the context, we will begin our reading at verse 10.
You can also use this guide by Fr. Cielo Almazan