What if Everything You Thought You Knew Was Wrong?

What is it to be washed with the blood and Spirit of Christ? It is to have the forgiveness of sins from God through grace, for the sake of Christ's blood, which He shed for us in His sacrifice on the cross; and also, to be renewed by the Holy Spirit and sanctified to be members of Christ, that so we may more and more die unto sin and lead holy and unblamable lives. Where has Christ promised that we are as certainly washed with His blood and Spirit as with the water of Baptism? In the institution of Baptism, which says: "Go ye, therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost. He that believeth and is baptized shall be saved; but he that believeth not shall be damned." This promise is also repeated, where Scripture calls Baptism the washing of regeneration, and the washing away of sins. Is then the outward washing with water itself the washing away of sins? No, for only the blood of Jesus Christ and the Holy Spirit cleanse us from all sin. Why then does the Holy Ghost call Baptism the washing of regeneration and the washing away of sins? God speaks thus not without great cause, namely, not only to teach us thereby that like as the filthiness of the body is taken away by water, so our sins are taken away by the blood and Spirit of Christ; but much more, that by this divine pledge and token He may assure us, that we are as really washed from our sins spiritually as our bodies are washed with water. – The Heidelberg Catechism, Q/A 70-73