What I am about to write may not work every Sunday!
Yesterday, the gospel reading, Matthew 5:13-20, had a certain complexity: the lovely and inspiring images of salt and light combined with a potentially very complicated set of verses on the law (complicated, e.g., in relation to explaining grace and faith). What to do?
It happened that I wrote one sermon, then another. I think what drove me to ditch the first was that it led into the complexity of the verses about Jesus' fulfilling the law without making a good relevant connection to our lives today.
The helpful idea which came to mind - thank you Lord - was to begin the sermon by asking what Jesus might have said were he at Waitangi yesterday or walking about in Tahrir Square, Cairo, where thousands of protestors have been gathering through the last week or so. That led me to suggest Jesus might have talked about the law first (connecting the law of Moses as a recipe for a just, healthy and godly society, with the respective situations of Aotearoa NZ and Egypt in which not everything is just, healthy or godly), and then about being salt and light.
The simple device of asking what Jesus might say in today's situation helped enormously with moving from the gospel passage as an academic challenge (what does salt of the earth mean, what is light of the world all about, why does Jesus say what he says about the law) to the gospel as a living word for today.
If a key to great sermons is telling stories (Bible stories, real life today stories) then one possibility, as happened yesterday, is to tell the Bible story as though it is happening today: if Jesus were in situation X, then, on the basis of our gospel reading, he would say Y.