In the first statement, Christ clarifies what is necessary for entering ("...no one can enter the kingdom of God unless he is born of water and the Spirit."), which is the positive, in the next, He disabuses Nicodemus of his misunderstanding ("Can a man reenter his mother's womb and be 'born again'?" "No, Nicodemus, flesh births flesh, but what I'm talking about is being born spiritually--spirit gives birth to spirit."), which is the negative.
These are two different purposes in speaking. The content needn't parallel.
The content needn't but it does! Paul expands on this thought in Romans.
Romans 2:28-29
King James Version
28 For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh:
29 But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.
Pharasaic Judaism taught as I showed that Jews by simple birth were members of the kingdom. Jesus and Paul taught that both a natural birth and spiritual birth are what is required.
John 3:3-7
King James Version
3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.
4 Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?
5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
7 Marvel not that I said unto thee, Ye must be born again.
Vse. 3&4 Jesus brings in the new concept needed to be born again. Once again Nicodemus was born again the four out of the possible 6 ways He could be in Pharasaic Judaism. bar-mitzvah, marriage, being rabbi, becoming a rabbi of rabbis. The term bortn again was not unkn own in Jesus day. It was spoken often in rabbinic circles.
Rabbi J. Cohen Halachic questions Born again Jews (jEWISH PRESS 10/5/90
Rabbi Judah in Gerimn 2.6
b.. Yebamoth 62a
b. Sanhedrin 58a;b
Yebamoth 23a
D Daube NT and Rabbinic Judaism (Hendrickson Publishers 1956 pp 112-113
E Schurer History of the Jewish People in the age of Jesus Christ (Edinburgh T.&T Clark 1979) 2:420 et. al.
As I showed this was a natural conversation not shrouded in metaphors or allegories.
As I linked to the Midrash Rabba, the mindset of the day was that it was enough to be born Jewish to be a member of the kingdom.
the reason why water here is not baptism (immersion) is that Nicodemus had u8ndergone many ritual baptisms (immersions).
the reason why water here is not a metaphor for the word is that Nicodemus was well versed in the word.
Jesus introduced a brand new concept to Israel, to be born from above! This was unknown to Israel of the day! A natural birth (water/flesh) was not enough to see the kingdom, but a spiritual birth was also required. that is why Jesus said one must be born of water AND the spirit. The new birth does not have two parts to accomplish it. we are not born of baptism or the word AND the Spirit- we are born of the spirit alone
People come up with convoluted arguments to defend being born of the word when it is far more simpler as I have shown and demonstrated.