Pope Shenouda III
Baptism is the action of being buried with Christ and tasting death with Him, as the Apostle says: "Therefore we were buried with Him through baptism into death" (Rom.6: 4) and we were "buried with Him in baptism" (Col.2: 12). The action of burying cannot be achieved except by immersion. The coming up out of the font signifies rising with Christ after having died and been buried with Him, whereas sprinkling does not express the action of dying and rising.