Without the presence of the Spirit there is no conviction, no regeneration, no sanctification, no cleansing, no acceptable works . . . Life is in the quickening Spirit. — W A. CRISWELL

 
BIRTH and rebirth. Both are the result of the operation of the Holy Spirit. Just as nothing can live biologically apart from the power of the Holy Spirit, so no man can come alive to God apart from the Spirit’s work
In His discourse with Nicodemus, Jesus said this about the Holy Spirit:
Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God. (John 3:3)
To be “born again” is to experience a second genesis. It is a new beginning, a fresh start in life. When something is started, we say that it is generated. If it is started again, it is regenerated. The Greek verb geniauo that is translated as “generate” means “to be,” “to become,” or “to happen.” Regeneration by the Holy Spirit is a change. It is a radical change into a new kind of being.
To be regenerated does not mean that we are changed from a human being into a divine being. It does mean that we are changed from spiritually dead human beings into spiritually alive human beings.
Spiritually dead persons are incapable of seeing the kingdom of God. It is invisible to them, not because the kingdom itself is invisible, but because the spiritually dead are also spiritually blind.
REGENERATION AS NECESSARY
When Jesus uses the word unless in speaking to Nicodemus, He is stating what we call a necessary condition. A necessary condition is an absolute prerequisite for a desired result to take place. We cannot have fire without the presence of oxygen because oxygen is a necessary condition for fire.
In the jargon of Christianity people speak of “born again” Christians. Technically speaking, this phrase is redundant. If a person is not born again, if he is not regenerate, then he is not a Christian. He may be a member of a Christian church. He may profess to be a Christian. But unless a person is regenerate, he is not in Christ, and Christ is not in him.
The word unless makes regeneration a sine qua non of salvation. No regeneration, no eternal life. Without regeneration a person can neither see the kingdom nor enter the kingdom.
When Nicodemus was puzzled by Jesus’ teaching he replied:
How can a man be born when be is old? Can he enter a second time into his mother’s womb and be born? (John 3:4)
Nicodemus’s response almost seems like an attempt to ridicule Jesus’ teaching. In crass terms he suggests that Jesus must mean that a fully grown person must attempt the impossible task of returning to his mother’s womb.
Nicodemus failed to distinguish biological birth from spiritual birth. He didn’t differentiate between flesh and spirit. Jesus answered his response by saying,
Most assuredly, I say to you, unless one is born of the water and the Spirit, he cannot enter 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.” (John 3:5-7)
Again Jesus prefaces His words by saying, “Most assuredly, I say to you . . .” The “most assuredly”— the Hebrew amen, carried over into the New Testament — indicates strong emphasis. That is, when Jesus spoke of regeneration as a necessary condition for seeing and entering the kingdom of God, he stated this necessary condition emphatically. To argue against the need of rebirth to be a Christian, as many of our contemporaries frequently do, is to stand in clear opposition to the emphatic teaching of Christ.
The word cannot is also crucial to Jesus’ teaching. It is a negative word that deals with ability or possibility. Without regeneration no one (universal negative) is able to enter the kingdom of God. There are no exceptions. It is impossible to enter God’s kingdom without a rebirth.
No one is born a Christian. No one is born biologically into the kingdom of God. The first birth is one that is of the flesh. Flesh begets flesh. It cannot produce spirit.
Later in John’s Gospel, Jesus adds this comment:
It is the Spirit who gives life; the flesh profits nothing. (John 6:2 3)
When Martin Luther was debating whether fallen man is utterly dependent upon the Holy Spirit for regeneration, he cited this text and added: “The flesh profits nothing. And that ‘nothing’ is not a ‘little something.’”
The flesh is not merely weak with respect to the power of rebirth. It is utterly impotent. It has no power whatever to effect rebirth. It cannot aid or enhance the Spirit’s work. All that the flesh yields is more flesh. It cannot yield an ounce of Spirit. The nothing is not a little something.
Finally Jesus says, “You must be born again.” If there is the slightest ambiguity with the use of the conditional word unless, the ambiguity completely evaporates with the word must.