By all accounts, the modern ecumenical movement is not moving much these days. Despite dramatic breakthroughs in the past few decades, the quest for a visibly united church--in which there is common confession of the apostolic faith, full Eucharistic communion, and mutual recognition of members and ministers--now meets with indifference by many, impatience by some, and outright hostility by others. In part, this is because the movement has not given...