Asking about the emergence of Christian material culture is something like asking when a river becomes a river. Countless drops of water fall on innumerable hillsides and plains, and make their way downhill, following the pull of gravity until they coalesce into rivulets and trickles. Those in turn gather into larger flows – streams, creeks, and washes – which combine and combine again into stronger and fuller courses. All the rivers of the world (the Nile, the Danube, the Congo, the Ganges, and the Yangtze, as well as the smaller and more anonymous ones) begin this way, fed by tributaries and histories of rain. When does the river become a river? We can point confidently to the mouth of the delta where the river empties out into the Gulf of Mexico and call that “the Mississippi,” but we must also recognize that its outflow represents a watershed draining a substantial part of a continent.