Kendy:
I am not entirely sure what you mean by faith presupposes the sacraments.
Faith goes before the sacraments. Catholics participate in the sacraments as a result of their faith. In the case of adult baptism, the adult asks for baptism because of his faith in Christ. In the case of infant baptism, the parents request baptism for their child because of their faith. In both cases, faith exists before the sacrament takes place.
I looked up “regeneration” in the Catechism to be sure I understood the term correctly. (CCC 1213, 1215, 784, 872, 1262; see also baptism.) I really liked the explanation so I cut and pasted a large section that explains Catholic teaching on being baptised and born again, and I highlighted parts I found most interesting.
**VII. THE GRACE OF BAPTISM **
1262 The different effects of Baptism are signified by the perceptible elements of the sacramental rite. Immersion in water symbolizes not only death and purification, but also regeneration and renewal. Thus the two principal effects are purification from sins and new birth in the Holy Spirit.65
For the forgiveness of sins . . .
1263 By Baptism
all sins are forgiven, original sin and all personal sins, as well as all punishment for sin.66 In those who have been reborn nothing remains that would impede their entry into the Kingdom of God, neither Adam’s sin, nor personal sin, nor the consequences of sin, the gravest of which is separation from God.
1264 Yet certain temporal consequences of sin remain in the baptized, such as suffering, illness, death, and such frailties inherent in life as weaknesses of character, and so on, as well as an inclination to sin that Tradition calls
concupiscence, or metaphorically, “the tinder for sin”
(fomes peccati); since concupiscence “is left for us to wrestle with, **it cannot harm those who do not consent but manfully resist it by the grace of Jesus Christ.”**67 Indeed, "an athlete is not crowned unless he competes according to the rules."68
"A new creature"
1265 Baptism not only purifies from all sins, but also makes the neophyte “a new creature,” an adopted son of God, who has become a "partaker of the divine nature,"69 member of Christ and co-heir with him,70 and a temple of the Holy Spirit.71
1266 The Most Holy Trinity gives the baptized sanctifying grace, the
grace of justification:
- enabling them to believe in God, to hope in him, and to love him through the theological virtues;
- giving them the power to live and act under the prompting of the Holy Spirit through the gifts of the Holy Spirit;
- allowing them to grow in goodness through the moral virtues.
Thus the whole organism of the Christian’s supernatural life has its roots in Baptism.