Belgic Confession Article 34 (Part I)
We believe and confess that Jesus Christ, in whom the law is fulfilled, has by his shed blood put an end to every other shedding of blood, which anyone might do or wish to do in order to atone or satisfy for sins.
Having abolished circumcision, which was done with blood, he established in its place the sacrament of baptism. By it we are received into God’s church and set apart from all other people and alien religions, that we may be dedicated entirely to him, bearing his mark and sign. It also witnesses to us that he will be our God forever, since he is our gracious Father.
Therefore he has commanded that all those who belong to him be baptized with pure water in the name of the Father, and the Son, and the Holy Spirit.
In this way he signifies to us that just as water washes away the dirt of the body when it is poured on us and also is seen on the body of the baptized when it is sprinkled on him, so too the blood of Christ does the same thing internally, in the soul, by the Holy Spirit. It washes and cleanses it from its sins and transforms us from being the children of wrath into the children of God.
This does not happen by the physical water but by the sprinkling of the precious blood of the Son of God, who is our Red Sea, through which we must pass to escape the tyranny of Pharaoh, who is the devil, and to enter the spiritual land of Canaan.
So ministers, as far as their work is concerned, give us the sacrament and what is visible, but our Lord gives what the sacrament signifies-- namely the invisible gifts and graces; washing, purifying, and cleansing our souls of all filth and unrighteousness...