“Preaching is more than the oral communication of information, no matter how biblical and divine that information may be. Rather, we should think in terms of what might be called “re-revelation.” Across the centuries, God disclosed himself – he revealed himself – in great events (eg. the burning bush, the exodus, the resurrection of Jesus); he disclosed himself supremely in the person of his Son. But very commonly he revealed himself by his words. Perennially we read, “The word of the Lord came to such-and-such a prophet.” So when that Word is re-announced, there is a sense in which God, who revealed himself by that Word in the past, is re-revealing himself by that same Word once again.
Preachers must bear this in mind. Their aim is more than to explain the Bible, however important that aim is. They want the proclamation of God’s Word to be a revelatory event, a moment when God discloses himself afresh, a time when the people of God know that they have met with the living God. They know full well that for the Scriptures to have this revelatory impact the Spirit of God must apply that Word deeply to the human heart, so that preaching must never be seen as a mere subset of public oratory. Both the content (the Bible is God’s Word) and the transformative empowering (the Spirit himself) transcend any merely mechanical view of preaching.”
D.A.Carson, ‘Challenges for the 21st Century Pulpit’, in L.Ryken & T.Wilson (eds.), Preach the Word: Essays on Expository Preaching in Honor of R.Kent Hughes (Wheaton: Crossway, 2007), 176.