Catechism of the Catholic Church

1217 In the liturgy of the Easter Vigil, during the blessing of the baptismal water, the Church solemnly commemorates the great events in salvation history that already prefigured the mystery of Baptism:

Father, you give us grace through sacramental signs
which tell us of the wonders of your unseen power.

In Baptism we use your gift of water,
which you have made a rich symbol
of the grace you give us in this sacrament. ¹¹

1218 Since the beginning of the world, water, so humble and wonderful a creature, has been the source of life and fruitfulness. Sacred Scripture sees it as "oveshadowed" by the Spirit of God: ¹²

At the very dawn of creation
your Spirit breathed on the waters,
making them the wellspring of all holiness. ¹³

1219 The Church has seen in Noah's ark a prefiguring of salvation by Baptism, for by it "a few, that is, eight persons, were saved through water": ¹⁴

The waters of the great flood
you made a sign of the waters of Baptism,
that make an end of sin and a new beginning of goodness. ¹⁵

1220 If water springing up from the earth symbolizes life, the water of the sea is a symbol of death and so can represent the mystery of the cross. By this symbolism Baptism signifies communion with Christ's death.

1221 But above all, the crossing of the Red Sea, literally the liberation of Israel from the slavery of Egypt, announces the liberation wrought by Baptism:

You freed the children of Abraham from the slavery of Pharaoh,
bringing them dry-shod through the waters of the Red Sea,
to be an image of the people set free in Baptism. ¹⁶

1222 Finally, Baptism is prefigured in the crossing of the Jordan River by which the People of God received the gift of the land promised to Abraham's descendants, an image of eternal life. The promise of this blessed inheritance is fulfilled in the New Covenant.