On the small, barren island of Likoma in Africa's Lake Nyasa stands a great cathedral. Built by native Anglican converts a century ago, it was long the center of Anglican missionary work in Nyasaland and a showpiece of transplanted Christianity. Today, huge cracks threaten to bring down the remnants of its walls, and its stained-glass windows hang crazily from their worm-eaten wooden frames.
Witch doctors and nationalist prophets have confused and corroded the congregation. Recently, one of the local splinter-sect "messiahs" announced that he meant to establish headquarters on the island, and the missionary priests resorted to a theatrical gesture. They...