Is church membership enough?
The Bible tells us that there was a man by the name of Nicodemus.
He was a Pharisee and he was a ruler of the Jews.
In other words, he was a well educated, devoutly religious man.
Apparently he had some compelling curiosity about spiritual matters because one evening, he personally sought out Christ.
Evidently he had seen some of the astounding miracles which Christ had done and as a result was motivated to find out more about the true identity of Christ.
In his initial greeting, Nicodemus says to Christ; "Rabbi, we know that You have come from God as a teacher; for no one can do these signs You do unless God is with him."
No doubt, Nicodemus was somewhat taken back by Christ’s response.
Instead of directly satisfying Nicodemus’ curiosity, Christ spoke words that were calculated to arouse his curiosity about the state of his own soul.
"Truly, truly, I say to you, unless one is born again, he cannot see the kingdom of God."
Nicodemus had never heard of such a thing and replies with words which reveal he failed to comprehend the spiritual truth which Christ was conveying. Nicodemus said to Him, "How can a man be born when he is old? He cannot enter a second time into his mother’s womb and be born, can he?"
Christ then makes a statement which further clarifies the issue, "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’"
Christ made it clear that Nicodemus’ education and his being devoutly religious was not enough to qualify him to enter the kingdom of God. In doing so, Christ made a clear distinction between the physical birth and the spiritual birth.
When Christ said, "That which is born of the flesh is flesh...."
He meant more than the mere fact that the results of a biological process produces that which is physical in nature. He meant the product of the biological process brings into the world another sinner.
That which is born of the flesh, will manifest that it is flesh, by the way it behaves.
In great contrast, Christ said, "that which is born of the Spirit is spirit."
In other words, the result of the regenerating work of the Holy Spirit is a new nature which manifests itself in the way it behaves.
Unless and until the Holy Spirit sovereignly regenerates the soul, there is no spiritual life.
Where there is no spiritual life, you have only the physical, and there is no way that one can "Christianize" the physical so as to qualify it to enter the kingdom of God. That is why Christ insisted, "Truly, truly, I say to you, unless one is born again, he cannot see the kingdom of God."