Water washes, it gives life, and it can bring about death. When a person is baptized they are baptized into the death of Christ, in order to rise in the new life of the Spirit by the death and resurrection of Jesus having been washed from their sins. Baptism is the sacrament by which we can enter the other sacraments, and so must be received first before any other sacrament.
“Holy Baptism is the basis of the whole Christian life, the gateway to life in the Spirit, 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'” (CCC, 1213).