There was a man of the Pharisees named Nicodemus, a ruler of the Jews. This man came to Jesus by night and said to Him, “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.”
Jesus answered and said to him, “Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.”
Nicodemus said to Him, “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?”
Jesus answered, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. 6 That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’ The wind blows where it wishes, and you hear the sound of it, but cannot tell where it comes from and where it goes. So is everyone who is born of the Spirit.”
Nicodemus answered and said to Him, “How can these things be?”
Jesus answered and said to him, “Are you the teacher of Israel, and do not know these things? Most assuredly, I say to you, We speak what We know and testify what We have seen, and you do not receive Our witness. If I have told you earthly things and you do not believe, how will you believe if I tell you heavenly things? No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven. And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish but have eternal life. For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
What does this mean? It means that we have died to self and now live by faith in Jesus Christ for both our forgiveness from sin and eternal salvation. The Apostle Paul writes:
I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me. (Galatians 2:20)
It means that we are now led by the Spirit of God and not our flesh:
Therefore, brethren, we are debtors—not to the flesh, to live according to the flesh. For if you live according to the flesh you will die; but if by the Spirit you put to death the deeds of the body, you will live. For as many as are led by the Spirit of God, these are sons of God. (Romans 8:12-14)
Does it mean that we have our ticket punched for heaven? By no means! We read in the Bool of Hebrews:
Let us hold fast to the confession of our hope without wavering, for he who has promised is faithful. And let us consider how to provoke one another to love and good deeds, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day approaching.
For if we willfully persist in sin after having received the knowledge of the truth, there no longer remains a sacrifice for sins, but a fearful prospect of judgment, and a fury of fire that will consume the adversaries. (Hebrews 10:23-27)