One of the things our brethren across the pond are rather better at than we are is big and optimistic thinking, dreaming and planning.
For example, you're New York and some terrorists fly a plane or two into a couple of your biggest baddest buildings. What do you do? You reply by saying 'tell you what, we'll build one building covering the surface area of the two and taller than the previous two, and we'll make it pretty impossible for people to fly planes into it. oh yeah, and we'll call it something like Freedom Tower.' Ok, so us Brits choke slightly on the implied jingoism and raise our eyebrows at the imperialistic arrogance that might stand behind that sort of thing. But 10/10 for sheer in-your-face positive thinking.
That sort of optimistic big-thinking can be found in the American church too. And when it's combined with Reformed theology and Gospel confidence, I can't help but see it as a good thing, and something we could do with spades more of here in the UK, where we've managed to find theological glosses for our in-built cynicism and sanctified our smallness.
E.g., Redeemer Presbyterian Church think big. They're optimistic about the depth and breadth of the gospel's power to change their city. They're working and praying towards the cultural renewal, conversion and transformation of New York. That's all. Oh, and while they're at it they want to help others in the US and some 50 other major cities around the world do that sort of thing too.
Now, whilst the 1,000+ caveats, questions, qualifications and worries about big visions flood your mind (many of which might be necessary and godly, many of which Redeemer and co. would go along with), remember that God's ambition for the world and for the glory of his Son is a lot bigger than Tim Keller's. Daniel 7:13-14, 2 Cor 10:4-6, Mark 4:20