Book excerpt: Christians chronically and desperately need prophecy, says award winning biblical scholar Luke Timothy Johnson. In this and every age, the church needs the bold proclamation of God's transforming vision to challenge its very human tendency toward expediency and self interest -- to jolt it into new insight and energy. For Johnson, the New Testament books Luke and Acts provide that much-needed jolt to conventional wisdom. To read Luke-Acts as a literary unit, he says, is to uncover a startling prophetic vision of Jesus and the church -- one that imagines a reality very different from the one humans would construct on their own. Johnson identifies in Luke's writings an ongoing call for today's church, grounded in the prophetic ministry of Jesus Christ, to embody and enact God's vision for the world--from publisher's website.