MarkT said:
....I think it's more like John's baptism preps us for the way because John 'prepared the way of the Lord'.....
What 20th century individuals think is of little consequence. What the Universal belief of the early Church was is what guides us to proper understanding of the subject. The key Scripture reference to being "born again" or "regenerated" is John 3:5, where Jesus says, "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God." The early Christians uniformly identified this verse with baptism. Water baptism is the way, they said, that we are born again and receive new lifeâ€â€a fact that is supported elsewhere in Scripture (Rom. 6:3–4; Col. 2:12–13; Titus 3:5). No Church Father referred to John 3:5 as anything other than water baptism.
Justin Martyr:
"As many as are persuaded and believe that what we [Christians] teach and say is true, and undertake to be able to live accordingly, and instructed to pray and to entreat God with fasting, for the remission of their sins that are past, we pray and fast with them. Then they are brought by us where there is water and are regenerated in the same manner in which we were ourselves regenerated. For, in the name of God, the Father . . . and of our Savior Jesus Christ, and of the Holy Spirit [Matt. 28:19], they then receive the washing with water. For Christ also said, ‘Unless you are born again, you shall not enter into the kingdom of heaven’ [John 3:3]" (First Apology 61 [A.D. 151]).
Irenaeus:
"‘And [Naaman] dipped himself . . . seven times in the Jordan’ [2 Kgs. 5:14]. It was not for nothing that Naaman of old, when suffering from leprosy, was purified upon his being baptized, but [this served] as an indication to us. For as we are lepers in sin, we are made clean, by means of the sacred water and the invocation of the Lord, from our old transgressions, being spiritually regenerated as newborn babes, even as the Lord has declared: ‘Except a man be born again through water and the Spirit, he shall not enter into the kingdom of heaven’" (Fragment 34 [A.D. 190]).
Tertullian:
"[N]o one can attain salvation without baptism, especially in view of the declaration of the Lord, who says, ‘Unless a man shall be born of water, he shall not have life’" (Baptism 12:1 [A.D. 203]).
Hippolytus:
"The Father of immortality sent the immortal Son and Word into the world, who came to man in order to wash him with water and the Spirit; and he, begetting us again to incorruption of soul and body, breathed into us the Spirit of life, and endued us with an incorruptible panoply. If, therefore, man has become immortal, he will also be God. And if he is made God by water and the Holy Spirit after the regeneration of the laver he is found to be also joint-heir with Christ after the resurrection from the dead. Wherefore I preach to this effect: Come, all ye kindreds of the nations, to the immortality of the baptism" (Discourse on the Holy Theophany 8 [A.D. 217]).
Cyprian of Carthage:
"[When] they receive also the baptism of the Church . . . then finally can they be fully sanctified and be the sons of God . . . since it is written, ‘Except a man be born again of water and of the Spirit, he cannot enter into the kingdom of God’" (Letters 71[72]:1 [A.D. 253]).
Cyril of Jerusalem:
"Since man is of a twofold nature, composed of body and soul, the purification also is twofold: the corporeal for the corporeal and the incorporeal for the incorporeal. The water cleanses the body, and the Spirit seals the soul. . . . When you go down into the water, then, regard not simply the water, but look for salvation through the power of the Spirit. For without both you cannot attain to perfection. It is not I who says this, but the Lord Jesus Christ, who has the power in this matter. And he says, ‘Unless a man be born again,’ and he adds the words ‘of water and of the Spirit,’ ‘he cannot enter the kingdom of God.’ He that is baptized with water, but is not found worthy of the Spirit, does not receive the grace in perfection. Nor, if a man be virtuous in his deeds, but does not receive the seal by means of the water, shall he enter the kingdom of heaven. A bold saying, but not mine; for it is Jesus who has declared it" (Catechetical Lectures 3:4 [A.D. 350]).
Athanasius:
"[A]s we are all from earth and die in Adam, so being regenerated from above of water and Spirit, in the Christ we are all quickened" (Four Discourses Against the Arians 3:26[33] [A.D. 360]).
Basil the Great:
"This then is what it means to be ‘born again of water and Spirit’: Just as our dying is effected in the water [Rom. 6:3; Col. 2:12–13], our living is wrought through the Spirit. In three immersions and an equal number of invocations the great mystery of baptism is completed in such a way that the type of death may be shown figuratively, and that by the handing on of divine knowledge the souls of the baptized may be illuminated. If, therefore, there is any grace in the water, it is not from the nature of water, but from the Spirit’s presence there" (The Holy Spirit 15:35 [A.D. 375]).
Augustine:
"It is this one Spirit who makes it possible for an infant to be regenerated . . . when that infant is brought to baptism; and it is through this one Spirit that the infant so presented is reborn. For it is not written, ‘Unless a man be born again by the will of his parents’ or ‘by the faith of those presenting him or ministering to him,’ but, ‘Unless a man be born again of water and the Holy Spirit.’ The water, therefore, manifesting exteriorly the sacrament of grace, and the Spirit effecting interiorly the benefit of grace, both regenerate in one Christ that man who was generated in Adam" (Letters 98:2 [A.D. 412]).
"Those who, though they have not received the washing of regeneration, die for the confession of Christâ€â€it avails them just as much for the forgiveness of their sins as if they had been washed in the sacred font of baptism. For he that said, ‘If anyone is not reborn of water and the Spirit, he will not enter the kingdom of heaven,’ made an exception for them in that other statement in which he says no less generally, ‘Whoever confesses me before men, I too will confess him before my Father, who is in heaven’" [Matt. 10:32] (The City of God 13:7 [A.D. 419]).