1279 The fruit of Baptism, or baptismal grace, is a rich reality that includes forgiveness of original sin and all personal sins, birth into the new life by which man becomes an adoptive son of the Father, a member of Christ and a temple of the Holy Spirit. By this very fact the person baptized is incorporated into the Church, the Body of Christ, and made a sharer in the priesthood of Christ.
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. 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.
“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,” member of Christ and co-heir with him, and a temple of the Holy Spirit.
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.
Incorporated into the Church, the Body of Christ
1267 Baptism makes us members of the Body of Christ: “Therefore… we are members one of another.” Baptism incorporates us into the Church. From the baptismal fonts is born the one People of God of the New Covenant, which transcends all the natural or human limits of nations, cultures, races, and sexes: “For by one Spirit we were all baptized into one body.”
1268 The baptized have become “living stones” to be “built into a spiritual house, to be a holy priesthood.” By Baptism they share in the priesthood of Christ, in his prophetic and royal mission. They are “a chosen race, a royal priesthood, a holy nation, God’s own people, that [they] may declare the wonderful deeds of him who called [them] out of darkness into his marvelous light.” Baptism gives a share in the common priesthood of all believers.
The sacramental bond of the unity of Christians
1271 Baptism constitutes the foundation of communion among all Christians, including those who are not yet in full communion with the Catholic Church: “For men who believe in Christ and have been properly baptized are put in some, though imperfect, communion with the Catholic Church. Justified by faith in Baptism, [they] are incorporated into Christ; they therefore have a right to be called Christians, and with good reason are accepted as brothers by the children of the Catholic Church.” “Baptism therefore constitutes the sacramental bond of unity existing among all who through it are reborn.”
An indelible spiritual mark…
1272 Incorporated into Christ by Baptism, the person baptized is configured to Christ. Baptism seals the Christian with the indelible spiritual mark (character) of his belonging to Christ. No sin can erase this mark, even if sin prevents Baptism from bearing the fruits of salvation. Given once for all, Baptism cannot be repeated.
1273 Incorporated into the Church by Baptism, the faithful have received the sacramental character that consecrates them for Christian religious worship. The baptismal seal enables and commits Christians to serve God by a vital participation in the holy liturgy of the Church and to exercise their baptismal priesthood by the witness of holy lives and practical charity.
 2 Cor 5:17; 2 Pet 1:4; cf. Gal 4:5-7
 Cf. 1 Cor 6:15; 12:27; Rom 8:17
 Cf. 1 Cor 6:19
 Eph 4:25
 1 Cor 12:13
 1 Pet 2:5
 1 Pet 2:9
 UR 3
 UR 22 § 2
 Cf. Rom 8:29; Council of Trent (1547): DS 1609-1619
 Cf. LG 11
 Cf. LG 10
Excerpts from the English translation of the Catechism of the Catholic Church for use in the United States of America Copyright © 1994, United States Catholic Conference, Inc. – Libreria Editrice Vaticana. Used with Permission.