Truly, truly, I say unto you, unless one is born of water and the Spirit, he cannot enter into the kingdom of God.
(1) As far as I can find there is only one ordinance that deals with water--- baptism in water in the name of Christ.
(2) This baptism is for all nations, all creation, as many as God shall call to Himself.
(3) This baptism has biblical reference to becoming a disciple, repentance, forgiveness of sin. salvation, entering a relationship with Christ, dying with our Lord, being buried with our Lord, arising with our Lord, becoming a son of God, being clothed with Christ, receiving the Holy Spirit, appealing to God for a good conscience, perfecting our faith, etc.
(4) Water and Spirit are connected in Ez. 36: 25-27; Matt 3: 13-17; Acts 2: 37-39; Acts 10: 44- 48; Acts 8: 13- 15; Acts 19: 5,6.
So what to we do when looking for an understanding of this passage? We go to metaphors and doctrines and experiences.
May God bless us so that we might deny ourselves.