Nicodemus, a Pharisee and a ruler of the Jews came to Jesus by night confessing that they know he was a Man sent by God. Jesus made it clear that knowing that He was sent by God is not enough but that
Except a man be born again, he cannot enter into the kingdom of God.
Jesus went on to explain he that is born of the flesh is flesh and the Bible says flesh and blood cannot enter into the Kingdom of God. This is bacause the flesh is always in conflict with the Spirit. The works of the flesh and the fruit of the Spirit are listed in Galatians; sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. The fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. (Gal 5:16-25)
Why should we be born again?
THIS IS THE MOST INTERESTING BIT. We must be born again because we were born wrong. This is just like making the correction when we did some task wrong in school. Because we were born wrong, Romans 3:23 says ALL have sinned. In fact, if we want to know the perfect will of God, we must look at Jesus' example. When God decided to come to the earth: Immanuel-God with us, He bypassed the way you and I were born because it is wrong. He was born not by a product of a man and a woman meeting but by a virgin birth. That is why Jesus was sinless but all others have sinned. We therefore need to be born again.
We inherit our parents' DNA when we are born and that is why we look and behave like them- we desire to sin. But once we are born again, our nature becomes like that of God and we behave like Him and hate what He hates. We are no more slave to sin once we are born again.
John 4:24 says God is Spirit and they that are born again have the Spirit of God. They cannot please God that are of the flesh but as many that are led by the Spirit of God, they are the sons of God. There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh but after the Spirit. (Romans 8)
Remember, all our woes started in the Garden of Eden.
Today, many will ask the same question as Nicodemus How Can I Be Born Again?