Being born of “water and Spirit” is certainly about water baptism and being born of the Spirit. This is evident because flesh and blood cannot inherit the kingdom of God. Thus, being born of water isn't a natural birth and it isn’t an essential component of entering the kingdom of God.
John 3
5Jesus answered, “Very truly I tell you, no one can enter the kingdom of God unless they are born of water and the Spirit.6Flesh gives birth to flesh, but the Spirit gives birth to spirit. 7You should not be surprised at my saying, ‘You must be born again.’
Paul tried to make it clearer here, but he also noted it’s a mystery. However, a careful study of the baptism shows that it’s required to be resurrected. I haven’t seen many people even attempt to try to understand this, but that’s common.
1 Corinthians 15
50I declare to you, brothers and sisters, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. 51Listen, I tell you a mystery: We will not all sleep, but we will all be changed— 52in a flash, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed.
John 3
5Jesus answered, “Very truly I tell you, no one can enter the kingdom of God unless they are born of water and the Spirit.6Flesh gives birth to flesh, but the Spirit gives birth to spirit. 7You should not be surprised at my saying, ‘You must be born again.’
Paul tried to make it clearer here, but he also noted it’s a mystery. However, a careful study of the baptism shows that it’s required to be resurrected. I haven’t seen many people even attempt to try to understand this, but that’s common.
1 Corinthians 15
50I declare to you, brothers and sisters, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. 51Listen, I tell you a mystery: We will not all sleep, but we will all be changed— 52in a flash, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed.
I'm saying that Jesus was comparing Nicodemus' mention of water of the womb with what happens much later.. not connected with conversion.. being born of the Spirit.
So it isn't that water of the womb is conversion.. it's that being regenerated by the Holy Spirit is.