Let us go over these analogies. The first is that of the primordial waters sanctified by the Spirit. As the Spirit of God, hovering over these waters, raised up the first creation, so the same Spirit, hovering over the baptismal waters, raises up the new creation, effects our rebirth. The Spirit of God is the creative Spirit.
Christ's word refers to this aspect: "Unless a man be born again of water and the Spirit, he cannot enter the kingdom" (John 3:5). "Why are you immersed in water?" St. Ambrose asks the neophyte. "We read: Let the waters bring forth living things (Gen. 1:20). And things were born. This took place at the beginning of creation. But it was reserved to our own times that water should give you a new birth by grace."