The belief in immersion as the proper mode of baptism is based on the Bible for several reasons:

-- The English word “baptize” comes from a word in the Greek language—the language in which the New Testament originally was written—that means “to dip, submerge, or immerse.”

-- John the Baptist baptized Jesus in the Jordan River by immersion as Jesus began his public ministry (Matthew 3:13-17; Mark 1:9-11).

-- Christ’s disciples in New Testament times baptized by immersion (Acts 8:36-39).

-- Immersion is a means not only of declaring that Christ died, was buried and was resurrected to provide salvation but also of testifying about our own hope of resurrection (Romans 6:5).

-- The New Testament teaches that immersion is a way to symbolize that a believer has died to an old way and is alive to walk a new way in Christ (Romans 6:3-4; Colossians 2:11-12).

(From “Baptists: Two Ordinances Baptism and the Lord's Supper” PDF or text only)