In the sermon, the Word of God is brought to bear on the lives of the hearers. This is the equivalent of sitting at the feet of Jesus. But it's more than mere instruction.
Through the sermon, God speaks to us with his two-edged sword of condemnation and promise, Law and Gospel. The subject of the sermon is both God and us.
Through the sermon we come to a better understanding of ourselves, especially our need for God's forgiveness. But we also come face to face with God's mercy and love.
Week after week, God's faithful hear the voice of their Good Shepherd, preparing them, in a sense, for that final day when Jesus calls them to their eternal reward.