This book offers an introduction to some of the fundamental themes of theology. From the very beginning, however, it insists on the contribution to be found in the different Christian traditions. The reader is enabled to view these traditions as part of a common heritage. Drawing on the wealth of these understandings of what it is to be Christian can be an inspiration for those from very different church structures, and even for people who seek to understand their own spiritual journey and search for God, without identifying themselves or their journey with any particular church. A number of important theological questions are covered in the book. It starts with a look at theological method before examining the idea of divine revelation. This is followed by investigating the nature of authority and authorities in different churches and where these coincide and come into conflict. The historical and cultural contexts of theology and its roots in religious experience are also examined. Each theme has a biblical and patristic part, as well as a genuinely reciprocal discussion involving contemporary Catholic, Orthodox, and Protestant theologians.