It is the God ordained sign that you are in covenant relationship with God who fulfills His promises even when we don’t. Baptism is not a self-worked expression of our faith, but a freely-given symbol of God’s gracious promises. God chose us before we could believe; He loved us before we even knew how to love. Baptism signals our initiation into the “Household of God”.
We believe and practice baptism by full immersion because Jesus was baptised that way, and every baptism in the Bible was by immersion. We believe it best symbolises a burial and resurrection.