Water Baptism demonstrates and celebrates our decision to follow Jesus and is an outward sign/testimony of His inward work in our life. 

Water Baptism is a beautiful symbol of God’s grace:  Just as water cleanses the body, so grace cleanses the soul.  Being immersed in water identifies us with Christ’s death on the cross (we die to our sinful life).  His burial in the tomb, and His resurrection from the dead (our being raised to new life in Christ).

As they went along the road they came to some water; and the eunuch *said, “Look! Water! What prevents me from being baptized?” And Philip said, “If you believe with all your heart, you may.” And he answered and said, “I believe that Jesus Christ is the Son of God.”  And he ordered the chariot to stop; and they both went down into the water, Philip as well as the eunuch, and he baptized him.          

 - Acts 8:36-38

Jesus was baptized and we are simply following his example in doing the same. It is a next step in your relationship with him and a celebration of the new life he has given you.