The Ordinance of Baptism
It is a command.
Jesus Christ commands those who are his disciples be baptized. It is, however, voluntary.
What is its Purpose?
Baptism is the symbol or illustration of what has already taken place as far as the believer is concerned. The believer symbolically passes through death, burial and resurrection in the waters of baptism. Thus the believer is identified with Christ, whose death, burial and resurrection were on his behalf. The believer is publicly saying, "Christ did all that was necessary for my salvation on the cross, I believe it with all my heart, and I am expressing it outwardly in this way as He commanded"
What is the procedure for Baptism?
The first Christians were baptized by immersion (submersion). Therefore we believe this should be our model today. The symbolism of baptism (burial with Christ) likewise requires immersion.