"...I now believe that the church is not here to speak to the world. We preachers do not have as our task to provide the world with some reason for living or some meaning for its worldliness -- we do not believe that the world, on its own, can have a reason or a meaning for its life. The church is about a more imperialistic enterprise than a deferential speaking to the world. We are to let God destroy and create a world through our preaching."
(Karl Barth - found here)
I am more and more of the mind that the gospel is like a miracle drug - it is intensively attractive to the human being - and all that is needed to grow it is to set it free. Wherever the gospel is preached, there it will prosper. Which says something about churches which don't grow, IMHO.
(But of course, growth does not mean gospel, it doesn't work in reverse. A church which is growing isn't necessarily preaching the gospel, but a church which is declining almost certainly ISN'T preaching the gospel.)