Few Christians can talk about the Trinity clearly or intelligently. When we ask theologians to speak of the doctrine in plain terms, they are not always helpful either. The early ecumenical councils (Nicea and Chalcedon particularly) attempted to define aspects of the mystery with precision, but their philosophical language made it difficult for average believers to understand their pronouncements. Because of the complexity of trinitarian terminology, Christianity over the years seemed to lose something of its monotheistic character. Taylor demonstrates with clarity the role of the human...