As recently as the 1990s, commentators speculated that technology would make the world ‘flatter’, rendering cities less important. But this has not happened–cities are perhaps more than ever ‘crucially important for the human future and for world mission’ (CTC). What is the hand of God in the massive rise of urbanisation in our time? And how can we respond to this fact by giving urgent, strategic attention to urban mission? This article suggests four basic foundations to answer this call with an effective response that places cities at the heart of mission.