Summary: What are the signs of a person who is "born again"?
Nicodemus was a Pharisee and a member of the Sanhedrin, who, according to the Gospel of John, showed favour to Jesus. He appears three times in the plot: the first is when he visits Jesus one night to listen to his teachings (John 3:1-21); the second is when he states the law concerning the arrest of Jesus during the Feast of Tabernacles (John 7:45-51); and the last follows the Crucifixion, when he assists Joseph of Arimathea in preparing the corpse of Jesus for burial (John 19:39-42).
Though there is no clear source of information about this Nicodemus outside the Gospel of John, the Jewish Encyclopedia and many Biblical historians have theorized that he is identical to Nicodemus ben Gurion, mentioned in the Talmud as a wealthy and popular holy man reputed to have had miraculous powers. Christian tradition asserts that Nicodemus was martyred sometime in the first century.
So, here is a well-regarded religious leader who recognizes that he is lacking something and he comes to Jesus in the quiet of the night. During his incarnate ministry Jesus often points to the most religious people and tells them that they are lacking. How are they lacking?
One day God looks on the earth and sees all the evil going on. God tells the archangel Michael to take all the avenging angels (those are the angels that afflict the comfortable in administering God's righteous judgement) to earth and evaluate things. After all the avenging angels come back, Michael reports to God that things are 95% bad and 5% good on the earth. God thinks for a moment and tells the archangel Gabriel to take all the ministering angels (those are the angels that comfort the afflicted in administering God's compassionate mercy) to earth and evaluate things. This way God would get both points of view. After all the ministering angels come back, Gabriel reports back to God that things are 5% good and 95% bad on the earth. Seeing that there's so much bad and so little good on the earth, God decides to send a letter to the 5% that are good to encourage them and help keep them going. Do you know what the letter said? What, you didn't get on either!?
Most English Bibles contain three uses of the phrase born again. The first two are in the Gospel of John, Chapter 3,(John 3) verse 3, spoken by Jesus while speaking to Nicodemus. Nicodemus says that, because of his miracles, Jesus is known "to be a teacher come from God" and, recognizing that, even though he is a well-regarded religious leader, he lacks something in his life and addresses Jesus with his concerns. “Jesus tells Nicodemus: "Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God".
In verses 7 and 8, Jesus says:
Marvel not that I said unto thee, Ye must be born again. / The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.
The John Gospel was written in Greek, and the Greek word translated as again could mean from above.