CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 1262–1265

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.
1263 By Baptism all sins are forgiven, original sin and all personal sins, as well as all punishment for sin. 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." Indeed, "an athlete is not crowned unless he competes according to the rules."
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," member of Christ and co-heir with him, and a temple of the Holy Spirit.