I believe what Jesus said in John 3:5. He said a man must be born of water and Spirit to enter the kingdom of God. He did not say man has to be born of the word and the Spirit, or of the Spirit and the Spirit.
“Now there was a man of the Pharisees named Nicodemus, a ruler of the Jews. This man came to Jesus by night and said to him, “Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do unless God is with him.” Jesus answered him, “Truly, truly, I say to you, unless one is born again he cannot
see the kingdom of God.” Nicodemus said to him, “
How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” Jesus answered, “Truly, truly, I say to you, unless one is born of 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.’ The wind blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit.” Nicodemus said to him, “How can these things be?” Jesus answered him,
“Are you the teacher of Israel and yet you do not understand these things?”
John 3:1-10 ESV
https://bible.com/bible/59/jhn.3.1-9.ESV
Jesus said to Nicodemus “Are you the teacher of Israel and yet you do not understand these things.” Would Jesus have expected the teacher of Israel to understand Christian water baptism. Maybe I just don’t understand, but I don’t believe he would have. I think about things like how he had to open the minds of the apostles to understand the scriptures in Luke 24.
Here is another passage that mentions being born again.
“since you have been
born again, not of perishable seed but of imperishable, through the living and abiding word of God; for “All flesh is like grass and all its glory like the flower of grass. The grass withers, and the flower falls,
but the word of the Lord remains forever.” And this word is the good news that was preached to you.”
1 Peter 1:23-25 ESV
https://bible.com/bible/59/1pe.1.23-25.ESV
This seems to support the idea of the water being the word. However, there is also another possibility. Notice the idea of the perishable seed and the imperishable seed and think about this.
“But someone will ask, “How are the dead raised? With what kind of body do they come?” You foolish person! What you sow does not come to life unless it dies. And what you sow is not the body that is to be, but a bare kernel, perhaps of wheat or of some other grain. But God gives it a body as he has chosen, and to each kind of seed its own body. For not all flesh is the same, but there is one kind for humans, another for animals, another for birds, and another for fish. There are heavenly bodies and earthly bodies, but the glory of the heavenly is of one kind, and the glory of the earthly is of another. There is one glory of the sun, and another glory of the moon, and another glory of the stars; for star differs from star in glory. So is it with the resurrection of the dead. What is sown is
perishable; what is raised is imperishable. It is sown in dishonor; it is raised in glory. It is sown in weakness; it is raised in power. It is sown a natural body; it is raised a spiritual body. If there is a natural body, there is also a spiritual body. Thus it is written, “The first man Adam became a living being”; the last Adam became a life-giving spirit. But it is not the spiritual that is first but the natural, and then the spiritual. The first man was from the earth, a man of dust; the second man is from heaven. As was the man of dust, so also are those who are of the dust, and as is the man of heaven, so also are those who are of heaven. Just as we have borne the image of the man of dust, we shall also bear the image of the man of heaven. I tell you this, brothers: flesh and blood cannot inherit the kingdom of God, nor does the
perishable inherit the imperishable. Behold! I tell you a mystery. We shall not all sleep, but we shall all be changed, in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised
imperishable, and we shall be changed.
For this perishable body must put on the imperishable, and this mortal body must put on immortality. When the
perishable puts on the imperishable, and the mortal puts on immortality, then shall come to pass the saying that is written: “Death is swallowed up in victory.” “O death, where is your victory? O death, where is your sting?””
1 Corinthians 15:35-55 ESV
https://bible.com/bible/59/1co.15.35-55.ESV
Here in 1 Corinthians 15 we see an extended discussion about the natural body vs. the spiritual body. The point is also made that the natural body must come first and them the spiritual body. Also you see the idea that flesh and blood cannot inherit the kingdom of God. Therefore one must be born again as 1 Peter 1 says. Notice also that John 3 discusses how we see or enter the kingdom of God. So these passages are discussing similar things.
Could born of water be referring to the natural body? We see the womb of a wife or a bride referred to as water in Song of Solomon 4 and Proverbs 5. These are definitely things that Nicodemus should have known as the teacher of Israel.