A great mystery is declared today, for the Creator of all in the Jordan washes away your wickedness. And by His washing, He takes on the filth of your sin, the filth of the sin of the world. In exchange for your sin, He gives you His righteousness. By water, by that blessed flood and lavish washing away of sin, a great exchange takes place. The Sinless becomes the sinner, and you, the sinner, become the righteous one.
Why does the Pastor preach? Scripture explains that the role of preaching the Word of God is how saving faith is created: “How then will they call on Him in whom they have not believed? And how are they to believe in Him of whom they have never heard? And how are they to hear without someone preaching? And how are they to preach unless they are sent? As it is written, ‘How beautiful are the feet of those who preach the good news!’ … So faith comes from hearing, and hearing through the Word of Christ” (Romans 10:14-17). The Augsburg Confession, seeing this connection between the Preaching Office and saving faith, summarizes Scripture on the Office of the Holy Ministry in this way: “To obtain [saving, justifying] faith, God instituted the Office of Preaching, giving the Gospel and the Sacraments. Through these, as through means, He gives the Holy Spirit who produces faith, where and when He wills, in those who hear the Gospel. It teaches that we have a gracious God, not through our merit but through Christ’s merit, when we so believe” (AC V 1-3). The whole reason the Pastor preaches is so saving faith can be created, so we know that “we have a gracious God” who loves us and has saved us from our sin by the death and resurrection of Jesus Christ.