What is Baptism
Baptism is one of two ceremonial acts that we see modeled in the Bible. The other is communion. John the Baptist preached a baptism of repentance for the forgiveness of sins - with water baptism being the symbolic act representing the individual's inner commitment.
The message translation says this is Colossians 2:13-15 - "Going under the water was a burial of your old life; coming up out of it was a resurrection, God raising you from the dead as he did Christ. When you were stuck in your old sin-dead life, you were incapable of responding to God. God brought you alive—right along with Christ! Think of it! All sins forgiven, the slate wiped clean, that old arrest warrant canceled and nailed to Christ’s cross."
At Our Lord's, we don't see baptism as the saving act of a person's soul, but a public declaration of our new life in Christ. As we come out of the water, we not only celebrate our forgiveness of sins, but the fact that we have been "raised with Christ".