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 and are incorporated into the Church and made sharers in her mission. “Baptism is the sacrament of regeneration through water and in the Word.”
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.”
St. Mary Basilica Baptismal Font