John 3:1-15 (HCSB)
There was a man from the Pharisees named Nicodemus, a ruler of the Jews. This man came to Him at night and said, " Rabbi, we know that You have come from God as a teacher, for no one could perform these signs You do unless God were with him."
Jesus replied, " I assure you: Unless someone is born again, he cannot see the kingdom of God."
"But how can anyone be born when he is old?" Nicodemus asked Him. "Can he enter his mother's womb a second time and be born?"
Jesus answered, " I assure you: Unless someone is born of water and the Spirit, he cannot enter the kingdom of God. Whatever is born of the flesh is flesh, and whatever is born of the Spirit is spirit. Do not be amazed that I told you that you must be born again. The wind blows where it pleases, and you hear its sound, but you don't know where it comes from or where it is going. So it is with everyone born of the Spirit."
"How can these things be?" asked Nicodemus.
"Are you a teacher of Israel and don't know these things?" Jesus replied. "I assure you: We speak what We know and We testify to what We have seen, but you do not accept Our testimony. If I have told you about things that happen on earth and you don't believe, how will you believe if I tell you about things of heaven? No one has ascended into heaven except the One who descended from heaven --the Son of Man. Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up, so that everyone who believes in Him will have eternal life.