Baptism
The foundational sacrament of Christian initiation, through which one is born anew of water and the Holy Spirit, becoming a member of Christ's Body, the Church.
Baptism is the gateway to all other sacraments. It signifies and effects liberation from original sin and all personal sins, incorporating the baptized into Christ and making them a new creation. It is a spiritual rebirth, making one a child of God and an heir of heaven.
Scriptural Basis: Matthew 28:19 ('Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit'), Acts 2:38 ('Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit'), Romans 6:3-4 ('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.').
Removes all sin (original and personal), remits all punishment due to sin, makes one a member of Christ's Body (the Church), confers sanctifying grace, imprints an indelible spiritual mark (character) on the soul, gives birth to new life in the Holy Spirit, and makes one a partaker in the divine nature.
For infants, parental consent and a commitment by parents and godparents to raise the child in the Catholic faith. For adults, instruction in the faith (through the Rite of Christian Initiation of Adults - RCIA), a sincere desire to convert, and repentance for sins.
Matter and Form
The matter of Baptism is water (immersion, pouring, or sprinkling). The form is the words: 'I baptize you in the name of the Father, and of the Son, and of the Holy Spirit.'
Minister
The ordinary minister of Baptism is a bishop, priest, or deacon. In case of necessity, anyone, even a non-baptized person, can baptize if they intend to do what the Church does and use the proper form and matter.