The Making of the Creeds by Frances M. Young
In lucid and non-technical prose, Young demonstrates how and why the two most familiar Christian creeds - the Apostles' Creed and the Nicene Creed - came into being. She describes how creeds originated in instruction before baptism and have their roots in the New Testament itself. She then shows how the rise of Gnosticism and a tendancy towards fragmentation in the church made a clear statement of faith necessary, as well as outlining the various controversies which led to particular words and phrases being included in the creeds as we now have them. She then describes the construction of the great Christian doctrines of the Trinity and incarnation.