Man cannot change his own nature, but God can. Jesus is the One who makes all things new. Nicodemus. although a teacher in Israel was walking in spiritual darkness - He knew all about the Messiah but needed life before he had the light to see clearly. Christ showed him that he needed to be born again to see the kingdom of God and enter it. Nicodemus relied on his own good works for the benefits of heaven and didn't understand that he needed to be transformed to have a new nature and a new heart. Our own inability to acknowledge Christ is because of our sinful human nature - people love darkness rather than light. New life comes only through Christ, by being born again through the work of the Holy Spirit. It is in God's will that we are made alive, not by our own efforts. We are reminded of who we were, what we are now, which will help us to grow as Christians. The Holy Spirit sustains us in our battle with sin, helping us to hunger for God and His word. We need to look to Christ that we might live.