We are all used to having a sermon during a worship service. That's good. And it's also good to ask some questions about this thing called a sermon. So, here's one question. What is a sermon? We all know that it's someone talking, but is that all? The common opinion these days is that a sermon is the collected thoughts of a person on some topic related to the Bible. They are presented in the hope of helping the listeners to live well. That understanding is good as far as it goes, but it is incomplete. And the gaps allow problems to arise. So, let me add something to make it a bit more complete.
A sermon is preached on God's behalf. Our worship style is a dialogue. It's a conversation between God and us with one and then the other saying things. So, for example, God speaks in the Reading of the Law of God. We respond with our Confession of Sin. Then God responds with His Declaration of Pardon and on we go. Worship is a conversation between God and us.
So, what does this have to say about the sermon? Just as Todd speaks on God's behalf when he reads the Law of God, I speak on God's behalf when I preach from some text of the Bible. Now, that way of looking at the sermon won't work if it's just my thoughts on some topic. A sermon is to be the application of something God has said in the Bible. So, imagine that I preach a sermon about Paul's command, 'Husbands love your wives'. And then imagine that I explain what the Bible means by love and then tell all the husbands in the room that they must do what I just explained. What have I done? I haven't given my opinion on some topic. I have spoken on God's behalf. That's a sermon.