In this powerful and persuasive work trailblazing historian Gregory Riley traces the origins of Christianity beyond its familiar sources in Judaism and in the Hebrew Bible. journeying off the beaten path, Riley reveals other, lesser-known sources -- elements of Greek philosophy and science, Zoroastrianism, and the religions of ancient Mesopotamia and Egypt. "From the very beginning," writes Riley, "there were several varieties of Christians." The differences were greater, perhaps, than those seen in the Christianity of today. Dozens of sects arose in different cities of the first-century Greco-Roman world, all claiming to be the religion of the risen Christ. Ultimately, these early, doctrinally disparate Christianities led to the present-day diversity of the Church. Moving from the origins of Christianity to understanding Christianity, this remarkable book guides the reader through five major areas at the core of Christian faith. The rise of monotheism. The subsequent development of Christian Trinitarianism. The evolution of the Devil and eschatology. The development and the consequences of the concept of body and soul for humans. The meaning of Jesus as savior. In straightforward, accessible prose, Riley shows how an enriched understanding of Christianity can uncover new truths and new pathways to faith. Likening the history of Christianity to a great river, Riley illustrates the ebb and flow of the relationship between God and humanity over the centuries. There are contributions from each side, divine and human, in a relationship that stretches over thousands of years, from before the dawn of writing to the time of the early Christians, and beyond. The River of God is an original and masterly exploration of how the beliefs and experience of early Christianity evolved among its early adherents. Weaving historical, theological, scientific, and social developments and insights, Gregory Riley distills the history of Christianity into a superbly readable volume that has profound implications for both its present and future.