The new birth is a real work of the Spirit of God. It is no mere theological concept, or less, a simple metaphorical idea. It is an actual work of God in the spiritual realm, more, in the spirit of a person. JESUS said, “No one can enter the Kingdom of God unless he is born again.”
The understanding of the new birth is itself borne out quite plainly in the scriptures in this like.
God formed man from the dust of the earth, breathed in his nostrils and he became a living soul. This man was very good. He was at that time exactly as God created him to be without the taint of sin. He was, again, very good. He did not as yet have any flaw or defect, any marring of his being as soon resulted from his disobedience and the consequence of his sin.
God commanded the man not to eat of the fruit of the tree of the knowledge of good and evil. He said, “In the day you eat of it, you shall surely die.”
Man was created as a living being with a physical body and spirit from the breath of God which made him a living soul. Scripture expressly declares that man in the totality of his being is spirit, soul and body. And so, the man as created very good was spirit, soul and body without any defect from the effects of sin. He was walking and talking with his Creator in the garden in the cool of the day.
Then, he sinned. The warning was clear, and God cannot lie. “In the day you eat of it, you shall surely die.” And scripture demonstrates clearly that death is a separation. Physical death is the separation of the spirit from the body, and spiritual death is the separation of the spirit of man from the Spirit of God. And so it was that in the day that man disobeyed God, eating the forbidden fruit, engaging in willful disobedience and sin, that sin entered the world. In the same moment, the man also experienced spiritual death, the separation of the spirit of man from the Spirit of God. For God’s Spirit cannot dwell with sin. God is holy.
And so it was that, while the man did not die physically in that moment, not even in that day or even in many hundreds of years, yet God’s WORD stands firm that man did experience death in that same day. That is to say that man experienced spiritual death; his spirit experienced separation from the Spirit of God.
Years later, when the Spirit of God departed from the temple, the term ichabod was used to describe this departure. This word means “the glory has departed.” This term is quite useful in understanding what previously happened in the day of the man’s first sin and spiritual death. Many more years after that, after the earthly life of Messiah, the Spirit of God revealed that the new birth of which Messiah taught was succinctly described in the phrase, “He who is joined with the LORD is one spirit.”
By these later progressive revelations, we can more clearly understand the nature of spiritual death which came through the first man Adam, and then the new birth which came through the One Whom the scriptures declare to be the second Adam.
When God created the first man and breathed His Spirit into him, he came to life with a living body, soul and spirit. When man sinned, he remained alive with life still in his earthly body, but his human spirit was separated from the Spirit of the LORD. That is to say, that a person who has been born of the flesh, but not of the spirit is alive in the flesh, but not in the spirit. Then, when a person is born again, their spirit is brought back to life by grace through faith. Their spirit is revived, resurrected and raised to life. And so it is that when a person is joined with the LORD, he is again one spirit.
This, then is the New Birth.