-- Christians make up more than three-fourths of the U.S. adult population, at approximately 159 million, and come from more diverse backgrounds than ever before. -- Provides accurate information from a recognized scholar of comparative religions -- no prior knowledge required. -- Virtually no other pocket-sized titles taking a comparative-religion approach to Christianity. Christianity has always been America's predominant faith. Current studies show that Christianity's popularity is not letting up but that its ranks are growing. Moreover, it has been adopted by great numbers of people outside of Europe and North America, considered the largest religion in the world with 1.8 billion devotees. The Christianity of today, though based on traditional tenants of the faith, is richly varied in interpretation and practice around the world. The Pocket Idiot's Guide "RM" to Christianity starts by briefly tracing the origins of Christian thought with the teachings of Jesus of Nazareth and how his role as the Messiah transformed the faith. Following chapters will concisely present the growth of Christianity and its many traditions throughout the Middle Ages and finally to its period of reformation and resulting sectarian movements. Final sections will focus on the current globalization of Christianity, its effects on Christian practice and beliefs and the new challenges and opportunities the faith will confront going into the 21st century.