Read John 3:2-17.
The text tells us that Nicodemus, a Pharisee, came to Jesus at night seeking something more than the standard explanation for the work that the Jewish leadership had already seen Jesus do. However, Jesus got to the heart of the matter quickly in the conversation. He told Nicodemus that he must be “born again” in order to “see the kingdom of God.”
Why would someone need to be born again? This is the question that Nicodemus and we have to come to grips with as well. There is an invisible plague that affects all of humanity. That is the plague of sin. It separates us from God. People try many things in order to bridge that gap: religion, good deeds, and a “moral” life. Some attempt to ignore it altogether. But it is still there. The story of Christianity is that God, through Jesus Christ, bridged that gap for us. When we trust in His death and resurrection, Jesus makes it possible for us to become new people, literally “born again” and become part of the kingdom of God.
Mark Riser - Apologist 