The holy spirit is the Spirit of confession. As Christ Our Lord said, the Holy Spirit “will teach you all things and bring to your remembrance all that I have said to you.” He confesses Christ to us, and by the faith He creates in us, we are able to confess Christ to others. That’s the whole point of this Feast of Pentecost. At Christ’s Ascension He gave His Church the solemn task of making disciples, that is, Baptizing and teaching, administering the Lord’s Supper, and forgiving the sins of all who repent. So just ten days after Jesus ascended into heaven, He poured out the Holy Spirit on His chosen disciples. And the Holy Spirit caused the apostles to confess in amazing ways. At St. Luke recorded in Acts, the apostles preached in languages which they had not learned. They preached that Jesus Christ died to take away the sin of the world. They preached that He rose victorious from the grave, the Father accepting His atoning sacrifice. They preached that Christ was giving His forgiveness and eternal life through Baptism, the washing of rebirth. And because of their Holy Spirit-given confession of the faith about 3,000 people were saved that day.
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.