If you back up a few verses from today’s appointed Gospel, you find Jesus saying to the Jews, namely the Pharisees and the chief priests, “If you were Abraham’s children, you would do the works of Abraham” (8:39). What Jesus does in this intense confrontation—spanning verses 12 through 59 of John 8—is show the Jews, particularly the religious rulers, who trusted completely in their lineage as Abraham’s children, that what they trusted in was false. Yes, by birth they belong to Abraham’s lineage. But the true children of Abraham are those who have faith. Abraham’s children are those who do what God commands of them, no matter how much it confuses or enrages or grieves them, as seen clearly in today’s Old Testament Reading. Spiritually, these Jews who would not believe in Jesus were children of the devil, the father of lies (8:44). The people who boasted being God’s chosen people were anything but.
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.