CIC 694 Water. The symbolism of water signifies the Holy Spirit’s action in Baptism, since after the invocation of the Holy Spirit it becomes the efficacious sacramental sign of new birth: just as the gestation of our first birth took place in water, so the water of Baptism truly signifies that our birth into the divine life is given to us in the Holy Spirit. As “by one Spirit we were all baptized,” so we are also “made to drink of one Spirit.”1 Thus the Spirit is also personally the living water welling up from Christ crucified2 as its source and welling up in us to eternal life.3

CIC 1225 In his Passover Christ opened to all men the fountain of Baptism. He had already spoken of his Passion, which he was about to suffer in Jerusalem, as a “Baptism” with which he had to be baptized.4 The blood and water that flowed from the pierced side of the crucified Jesus are types of Baptism and the Eucharist, the sacraments of new life.5 From then on, it is possible “to be born of water and the Spirit”6 in order to enter the Kingdom of God.
See where you are baptized, see where Baptism comes from, if not from the cross of Christ, from his death. There is the whole mystery: he died for you. In him you are redeemed, in him you are saved.7

CIC 1847 “God created us without us: but he did not will to save us without us.”8 To receive his mercy, we must admit our faults. “If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness.”9

CIC 2780 We can invoke God as “Father” because he is revealed to us by his Son become man and because his Spirit makes him known to us. The personal relation of the Son to the Father is something that man cannot conceive of nor the angelic powers even dimly see: and yet, the Spirit of the Son grants a participation in that very relation to us who believe that Jesus is the Christ and that we are born of God.10

CIC 2790 Grammatically, “our” qualifies a reality common to more than one person. There is only one God, and he is recognized as Father by those who, through faith in his only Son, are reborn of him by water and the Spirit.11 The Church is this new communion of God and men. United with the only Son, who has become “the firstborn among many brethren,” she is in communion with one and the same Father in one and the same Holy Spirit.12 In praying “our” Father, each of the baptized is praying in this communion: “The company of those who believed were of one heart and soul.”13

1 1 Cor 12:13.
2 Jn 19:34; 1 Jn 5:8.
3 Cf. Jn 4:10-14; 738; Ex 17:1-6; Isa 55:1; Zech 14:8; 1 Cor 10:4; Rev 21:6; 22:17.
4 Mk 10:38; cf. Lk 12:50.
5 Cf. Jn 19:34; 1 Jn 5:6-8.
6 Cf. Jn 3:5.
7 St. Ambrose, De sacr. 2, 2, 6: PL 16, 444; cf. Jn 3:5.
8 St. Augustine, Sermo 169, 11, 13: PL 38, 923.
9 1 Jn 8-9.
10 Cf. Jn 1:1; 1 Jn 5:1.
11 Cf. 1 Jn 5:1; Jn 3:5.
12 Rom 8:29; Cf. Eph 4:4-6.
13 Acts 4:32.