Change agents are pioneers, entrepreneurs, innovators. They can be difficult, annoying, and demanding. But their calling is demanding too: to take a vision and wrench it into reality. When Steve Chalke was asked to be the senior minister of a dying inner-city church, he knew what he wanted: to make it into a Christian equivalent of a first-century synagogue. A place where the community gathered, not just to pray and hear sermons, but to be educated,...