Christian baptism is a sign from God that signifies inward cleansing and remission of sins (Acts 22:16; 1 Cor. 6:11; Eph. 5:25-27), Spirit-wrought regeneration and new life (Titus 3:5), and the abiding presence of the Holy Spirit as God’s seal testifying and guaranteeing that one will be kept safe in Christ forever (1 Cor. 12:13; Eph. 1:13-14). Baptism carries these meanings because fundamentally it signifies union with Christ in his death, burial, and resurrection (Rom. 6:3-7; Col. 2:11-12); and this union with Christ is the source of every element in our salvation (1 John 5:11-12). Receiving the sign in faith assures the persons baptized that God’s gift of new life in Christ is freely given to them. Baptism signifies a defining moment in a believer’s life because it signifies a new-creational engrafting into Christ’s risen life.
Christ instructed his disciples to baptize in the name of the Father, the Son, and the Holy Spirit (Matt. 28:19). This means that the covenant relation which baptism formally confers is one of acceptance by, communion with, and commitment to all three Persons of the Godhead.