For centuries, the missionary current flowed from West to Africa, carried on the same ships as colonial ambition. Now, a generation of African Christians is reversing that tide, filling European stadiums and planting churches in North American cities, driven by the conviction that the faith their ancestors received has grown cold in the hands of those who first delivered it. The numbers lend weight to their sense of calling: Christianity is contracting across Europe and North America even as it surges across Africa, and the question of whether fervent African faith can rekindle something lost