1. On one level a lunchbar talk is like a piano recital; it’s a cultural product.
The pianist would have some natural ability and would have ‘nurtured his nature’ or added graft to the gift.
He would learn attentively from excellent models, would draw on available resources (recordings, books etc), and he would seek feedback from peers. Lunchbar speakers must do the same.
Don’t believe the romantic myth of that you’ll sit down at the piano and be inspired (I tried that once). Nor believe the Christian myth that speakers should just stand up and be inspired.
An apologeticsy evangelistic lunchbar talk is a cultural product, but there’s more.
2. It happens to be a cultural product with clear Biblical precedents in Paul’s missionary preaching in Acts (compare Acts 13 & Acts 17), and it’s a cultural product that God clearly used and continues to use.
Jews believe in the promised Messiah and Pagans turn from ‘worthless things’ to the true and living God. I became a Christian through Lunchbars in Oxford in 2000. And it is the LORD who saves.
3. So should we be prepping or praying? This is obviously a false dichotomy.
The tension is best seen to be held in balance when Paul writes in Colossians 1:28-29
28Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ. 29For this I toil, struggling with all his energy that he powerfully works within me.