To begin let me say that instead of “born again,” the original Greek might have been better translated “born from above.” “Unless one is born from above he cannot see the kingdom of God.” There is another very common Greek word that means “again” but it’s not the word used here. The word used here has the primary meaning of “from above,” or similarly “from the top,” and this is how it is translated in its every other occurrence in the Gospel of John (3:31; 19:11, 23).
Not only in the Gospel of John, but in every other occurrence in the New Testament, the word most naturally means from above, or from the top. This seems to be how it should be understood in the passage, “Unless one is born from above he cannot see the kingdom of God” (Jn. 3:3).
The coming down of Jesus from heaven is a prominent theme throughout the Gospel of John.
No one has ascended into heaven except him who descended from heaven, the Son of Man (Jn. 3:13).
He who comes from above is above all (Jn. 3:31).
He said to them, “You are from below; I am from above. You are of this world; I am not of this world” (Jn. 8:23).This contrast is important and a frequently occurring theme in John’s Gospel. Jesus is from above. He is from heaven. We are from below, from the earth. And Jesus tells us that if we wish to see the kingdom of heaven, we must be born from above.
Nicodemus doesn’t understand Jesus’ meaning. He asks, “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” (Jn. 3:4) He is thinking in human terms. And Jesus rebukes him for not understanding. “Are you a teacher in Israel,” he says, “and you do not understand these things?” (v. 10).
Jesus is talking about a work of the Holy Spirit which is accomplished in the soul of man. It is the implanting of new spiritual life. It is a change which is wrought by the Holy Spirit in a man’s nature. It is a reversal of the moral and spiritual effects of the Fall.
When man fell into sin, there was a fundamental change that took place in his nature. He became a slave to sin and averse to all true spiritual good. Whereas, before the Fall righteousness came naturally to him and he had a taste for divine things, afterward sin was natural, and righteousness unnatural. Man lost his taste for things divine. He lost his taste for true spiritual good. Man in his fallen state is described in Job as drinking iniquity like water (Job 15:16). In other words, he has a thirst for sin. For some it is a thirst for very crass and obvious forms of sin. For others, it is a thirst for more refined and sophisticated forms. As Paul says, “The sins of some men are conspicuous, going before them to judgment, but the sins of others appear later” (1 Tim. 5:24). But everyone born since Adam has been affected by the Fall such that apart from divine grace he is wholly disinclined to what is spiritually good. He is averse to the things of God. Not that every man is equally wicked, or that every man is as evil as he could possibly be, but that every man—apart from divine grace—is naturally disinclined to love and obey God.
This is the condition of everyone who has been born since Adam. He is devoid of grace, devoid of the Spirit. He is earthly and natural, and nothing but flesh. That which is born of the flesh is flesh. That which is born to a fallen man is a fallen man.
But with the birth that comes from above, accomplished by the Spirit, all this changes. He is no longer merely an earthly man. Now there is a heavenly aspect to his being. He’s no longer limited by the flesh, but has the Spirit of God residing in him. He is no longer merely a natural man, but has a supernatural element to him. He’s been given a taste for divine things. He is enabled to believe and to turn away from sin.