The Bible requires of those who would enter the Kingdom of God that they must be born again. The Christmas season helps us understand this issue (063) because even Jesus was twice born--once physically, and again unto resurrection life. Acts 13:33 says that God the Father said to Jesus, the Son, when He was raised from the dead: "Thou art my Son, this day I have begotten Thee".
Since being born again is such a critical issue (those who are not twice-born, die twice--the Lake of Fire is called the Second Death), it is helpful for us to look into the two begettings of Jesus Christ.
The first begetting was by the Holy Spirit in the womb of Mary. This begetting was absolutely necessary to our salvation in that Jesus had to be human in order to die for humans. He had to become what we are (sinful) in order for us to become what He is (righteous): 2 Corinthians 5:21. That is not to say that He ever committed a sin, for He did not. But, He came to take our place under the wrath of God against sin. If He had not been born of woman, this would not have been possible.
However, our salvation does not rest exclusively on His humanity and death. If He had not been raised from the dead, His claims would have gone the route of all other religious leaders who made the claim to be able to give eternal life to their followers. Those claims were only as good as their power--which ended at death. But, Jesus' claims didn't end at death because He didn't. He was raised from the dead by the mighty power of God.
This is important in that it sheds light on the meaning of the requirement that we be born again. When Jesus was begotten the second time, it was to resurrection life. In the same way, when we are born again, we have resurrection life (eternal life) infused into us. Born again Christians have the power of resurrection at work in them unto real life. They are the only people on the planet that have a new quality of existence to their lives. Everyone else is simply physically alive. This life will end at the point of physical death. But, those who are twice born have eternal life resident in their bodies. Though the bodies still age and, eventually, die, the possessor of eternal life goes immediately into the experience of undiminished eternal life. This is how Jesus could say that those who believe in Him would never die. He did not mean that their bodies would not cease to function; He meant that when they did, their owners would be immediately transported into the presence of Jesus and life.
The Christmas season is the celebration of the time of Jesus' first birth. But, it is also a harbinger of His second begetting at the resurrection. As such it is a call to us to test ourselves to see if we have His resurrection life in us. If we have been born again, we have. If we have not been born again, we do not have His life in us.
That raises the question of how we are born again; a question we shall spend some effort trying to answer. (064)