Sacrament of Baptism: A Brief Introduction
(excerpts taken from the English translation of the Catechism of the Catholic Church for the United States of America copyright © 1994, United States Catholic Conference, Inc.—Libreria Editrice Vaticana. http://www.usccb.org/catechism)
Holy Baptism is the basis of the whole Christian life, the gateway to life in the Spirit (vitae spiritualis ianua),and the door which gives access to the other sacraments. Through Baptism we are freed from sin and reborn as sons of God; we become members of Christ, are incorporated into the Church and made sharers in her mission: “Baptism is the sacrament of regeneration through water and in the word.”
According to the Apostle Paul, the believer enters through Baptism into communion with Christ’s death, is buried with him, and rises with him:
Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.
The baptized have “put on Christ.” Through the Holy Spirit, Baptism is a bath that purifies, justifies, and sanctifies.
…Baptism is a bath of water in which the “imperishable seed” of the Word of God produces its life-giving effect. St. Augustine says of Baptism: “The word is brought to the material element, and it becomes a sacrament.”
The Lord himself affirms that Baptism is necessary for salvation. He also commands his disciples to proclaim the Gospel to all nations and to baptize them. Baptism is necessary for salvation for those to whom the Gospel has been proclaimed and who have had the possibility of asking for this sacrament. The Church does not know of any means other than Baptism that assures entry into eternal beatitude; this is why she takes care not to neglect the mission she has received from the Lord to see that all who can be baptized are “reborn of water and the Spirit.”
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.
Baptism imprints on the soul an indelible spiritual sign, the character, which consecrates the baptized person for Christian worship. Because of the character Baptism cannot be repeated.