Already have in this discussion about baptism. ;)
In John 3:5, the author is using the figure Hendiadys. For those unfamiliar with this figure of speech, I supply an exhaustive definition with examples from the bible for their edification:
Hendiadys; or, Two for One. Two words used, but only one thing meant.
Hen-di'-a-dys, from hen, "one", dia, "by", dis "two" (From duo, two) Literally, one by means of two. Two words employed, but only one thing, or idea, intended. One of the two words expresses the thing, and the other (of synonymous, or even different, signification, not a second thing or idea) intensifies it by being changed (if a noun) into an adjective of the superlative degree, which is, by this means, made especially emphatic.
The figure is truly oriental, and exceedingly picturesque. It is found in Latin as well as in Hebrew and Greek, and is very frequently used both in the Old and New Testaments.
The two words are of the same parts of speech: i.e., two nouns (or two verbs) always joined together by the conjunction "and". The two nouns are always in the same case.
Some examples:
"And Abel, he also brought of the firstlings of his flock, and of the fat thereof" Gen.4:4: i.e. he brought the firstlings of this flock, yes--and the fattest ones too, or the fattest firstlings of his flock, with emphasis on "fattest".
"Then the Lord rained upon Sodom and upon Gomorrah brimstone and fire from the Lord out of heaven"Gen.14:24: i.e. brimstone, yes- and burning brimstone too; or, simply "burning brimstone" with emphasis on "burning"
They "buried him in Ramah and his own city" 1 Sam.28:3: i.e., in Ramah, yes-even in his own city; or, in his own city, Ramah.
"Of fame and of glory" 1 Chron. 22:5; i.e., of glorious fame
"I love the Lord, because he hath heard my voice and my supplications" Ps. 66:1; i.e., my supplicating voice with emphasis on "supplicating".
"I am not able to endure your iniquity and assembly" Isa 1:13; i.e., your iniquity, yes-your iniquitous assemblies.
"Execute ye judgment and righteousness" Jer. 22:3; i.e., execute judgment, yes- and righteous judgment too.
"A day of trumpet and alarm" Zeph.1:16; i.e., an alarming trumpet.
"He shall baptize with the Holy Ghost and with fire". First observe that there are no articles. e.g. "en pneumati hagio kai puri" with Holy Spirit and fire, i.e. "with burning purifying spirit" Not two things, but one: Judgment!
The contrast was with John's baptism which was with water which mingled the chaff with the wheat. The new baptism is not like that. It separates the chaff from the wheat by burning it up as the Baptist points out: "whose fan is in his hand, and he will thoroughly purge his floor, and gather his wheat into his garner: but he will burn up the chaff with unquenchable fire."
"Except a man shall have been begotten of water and spirit."Jn.3:5; Again, there is no article to either of the two nouns.
That only one thing is meant by the two words is clear from verses 6 and 8, where only the Spirit (the one) is mentioned.
Christ is speaking to Nicodemus of "earthly things" (vs. 12). And as "a master in Israel", he knew perfectly well the prophecy of Ezek. 36: 25-27 concerning the kingdom. Concerning Israel, in the day of their restoration to their own land, The Lord had declared: "Then will I sprinkle clean water upon you, and ye shall be clean...And I will put my spirit within you, " etc.
The cleansing of that day is not to be with literal water, as in the ceremonial cleansings of the Law, but with the Spirit of God.
Hence, only one thing is meant: "Except a man be begotten of water, yes- and spiritual water too, he cannot enter into the kingdom of God". That spiritual water stands, by another figure (Metonymy), for the Holy Spirit Himself: as is clear from John 7:38,39: "water- (But this spake He of the Spirit, which they that believe on Him should receive...)".
Therefore, there is no reference here to ceremonial or ecclesiastical water- but to that baptism of the Spirit which is the one indispensable condition of entering into the kingdom of God; a moral sphere, which includes and embraces the Church of God, here and now, as well as the future kingdom foretold by God through the prophets.