Why do we preach in our Sunday worship services? What is preaching, anyway? And again, why do we give it such high priority in our Sunday worship services? Here’s one way to answer that from John Piper:
“...there are always two parts to true worship. We can say it in two pairs: there is seeing God and there is savoring God. You can't separate these. You must see him to savor him. And if you don't savor him when you see him, you insult him. Or another pair would be this: in worship there is always understanding with the mind and there is always feeling in the heart. Understanding must always be the foundation of feeling, or all we have is baseless emotionalism. But understanding of God that doesn't give rise to feeling for God becomes mere intellectualism and deadness. This is why the Bible continually calls us to think and consider and meditate and remember on the one hand, and to rejoice and fear and mourn and delight and hope and be glad on the other hand. Both are essential for worship.
“Now preaching is the form that the Word of God takes in worship because true preaching is the kind of speech that consistently unites these two aspects of worship, both in the way it is done and in the aims that it has. When Paul says to Timothy in 2 Timothy 4:2, ‘Preach the word,’ the word for ‘preach’ is a word for ‘herald’ or ‘announce’ or ‘proclaim’ (κηρυξον). It is not a simple word for teach or explain. It is what a town crier did: ‘Hear ye, Hear ye, Hear ye! The King has a proclamation of good news for all those who swear allegiance to his throne. Be it known to you that he will give eternal life to all who trust and love his Son.’ I call this heralding ‘exultation.’ Preaching is a public exultation over the truth that it brings. It is not disinterested or cool or neutral. It is passionate about what it says.
“Nevertheless this heralding contains teaching. You can see that as you look back to 2 Timothy 3:16 - the Scripture (which gives rise to preaching) is profitable for ‘teaching.’ And you can see it as you look ahead to the rest of 2 Timothy 4:2, ‘Preach the word; be ready in season and out of season; reprove, rebuke, exhort, with great patience and instruction.’ So preaching is expository. It deals with the Word of God. True preaching is not the opinions of a mere man. It is the faithful exposition of God's Word.”
Excerpted from The Place of Preaching in Worship.
Read the whole article/sermon at DesiringGod.com.