John 3:5 and baptism

Does John 3:5 'unless one is born of water and the Spirit he cannot enter the kingdom of God' say that baptism is required to be saved. Lets look at the context. Jesus Christ is talking to Nicodemus a jewish preacher about how one is saved. And He then quotes 3:5. What is He doing quoting something that hasnt come into existence. And he expects Nicodemus to understand. vs 10: 'Are you the teacher of Israel, and do not know these things?'. So it could possibly not have meant baptism.
After rebuking Nicodemus he goes on to explain that like those who looked to the bronze serpent on the cross which Moses lifted up were saved, those who look to Christ in faith to the cross are the ones saved. John 3:15,16,18 all say belief - faith is the one that saves. Isnt it interesting that the very serpent that was killing the Israelites, is what they had to look to, in order to be saved? Also why would Christ rebuke Nicodemus if he couldnt have possibly known what He was talking about? Why isnt baptism mentioned after Nicodemus was rebuked?
So what does John 3:5 mean? What is it that a jewish rabbi, well versed in the scriptures, would figure out from John 3:5? See Isaiah 12:3,35:6,55:1, Ezekiel 36:35, Jeremiah 2:13, Zecheriah 14:8 and figure it out for yourselves.
Whatever John 3:5 means it could possibly not mean baptism.
John the baptist - 'i baptize you with water but He shall baptize you with the Holy Spirit'. Note the contrast between water immersion (baptism) and Holy Spirit baptism. Christ came to baptize us with His Spirit not with water.