Here’s what he means by that: “How does this biblical text—its world of assumptions, attitudes, and application—cut against the grain of what passes for “common sense” in our world? Where’s the encounter or confrontation of this text with worldly ways of thinking and living? Where’s the sharp point of contradiction? Find the edge. The world says one thing; the Bible says another. Don’t stop planning your sermon until the edge is clear.”

Trevin gives an illuminating example of a sermon (of his) on the Lord’s Prayer that lacked the edge. Its early draft was fine; it was true, clear, well-structured and theologically sound. But it wasn’t very interesting. It didn’t say anything that most of the listeners didn’t already know, and nor did it say it in a way that they would find fresh, let alone electrifying. So he rewrote it, looking for the edge. He began with the question: “How does this line cut against the common sense of the world or the current practice of the church?” For example:

- How does praying to our Father expose our overly individualistic understandings of the Christian faith?
- How does the picture of him being in heaven reveal popular misunderstandings of heaven and earth and how they relate?
- What does it mean to pray for God’s name to be hallowed in a world where most people believe the purpose of life is to see one’s own name magnified?
- How does praying for daily bread stand out in a world that prizes independence and self-reliance?

Tim Keller was an expert at this. As Trevin points out, Keller identified five major narratives in our culture that the Scriptures regularly challenge, and regularly incorporated them into his own preaching: (1) rationality, (2) history, (3) society, (4) morality, and (5) identity. But this did not make him—and it should not make us—preachers who rail against the culture while leaving our own idols untouched. Rather, it made him—and it should make us—preachers who allow Scripture to challenge the falsehoods, assumptions and ideologies that percolate throughout our culture, including within our churches, workplaces and homes.

It’s a great piece. Read the whole thing here.