BusyTarpDuster2017 said:
What does the Catholic church believe happens at water baptism?
Before I respond to that I would also like to explain what Catholics believe about original sin. I'm not trying to be condescending, I really don't know what other faiths believe about it.
Original sin is something that were born with. In reality, it is not something we have, but rather something that we lack. Due to the fall of our first parents, we ALL lack sanctifying grace. Loosely, we have a hole in us. When we are baptized, our sins (including original sin) are washed away and we filled with sanctifying grace.
I'm going to use the
Catechism of the Catholic Church for specifics here (please take time to read this short, but incredibly rich section of the CCC:
ARTICLE 1
THE SACRAMENT OF BAPTISM1213 Holy Baptism is the basis of the whole Christian life, the gateway to life in the Spirit (vitae spiritualis ianua),4 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 in the word."5
I. WHAT IS THIS SACRAMENT CALLED?1214 This sacrament is called Baptism, after the central rite by which it is carried out: to baptize (Greek baptizein) means to "plunge" or "immerse"; the "plunge" into the water symbolizes the catechumen's burial into Christ's death, from which he rises up by resurrection with him, as "a new creature."6
1215 This sacrament is also called "the washing of regeneration and renewal by the Holy Spirit," for it signifies and actually brings about the birth of water and the Spirit without which no one "can enter the kingdom of God."7
VI. THE NECESSITY OF BAPTISM1257 The Lord himself affirms that Baptism is necessary for salvation.60 He also commands his disciples to proclaim the Gospel to all nations and to baptize them.61 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.62 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." God has bound salvation to the sacrament of Baptism, but he himself is not bound by his sacraments.
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.
Footnotes of bible references and Counsil documents are listed in the attached link.