Baptism - Triune Immersion
There is nothing special about the water. There is nothing magical about the act. We can go to heaven without being baptized. But Jesus asks us to do it as a testimony of what we believe... a symbol of our relationship with Him... a demonstration that we've left a former way of life to live a new life as children of God.
We believe that baptism symbolizes our moving from death to life, a cleansing, and the work of the Holy Spirit by which Jesus enters our lives. We believe that the Father, Son, and Holy Spirit are all involved in the miracle of salvation. When Jesus sent His followers around the world with the Gospel, He told them to baptize people "in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19). It's one reason why we dip people into the water three times, "In the name of the Father, and of the Son, and of the Holy Spirit." It is one baptism, but three times into the water.
Baptism is thus a three-in-one act of gratitude for God's triune involvement in our salvation.
[Excerpts from What is Baptism, The Readable Series - a ministry of CE National, 1994.