The origins of Christian thought occurred in a time and place that together occupy a prominent place in human history. Christianity’s origin is at the juncture of the old and the new, a time when Ancient History, whose record has largely been effaced from posterity, was fading away, and a more documented era in human history was beginning. Thus, the history of Christianity is able to contain both the mythic aspect of legend as well as the tangibility of contemporaneous occurrence.

The religions extant today, like Hinduism, Confucianism and Buddhism, that are senior to Christianity were formed at least a few hundred years before and much less, perhaps only patchy, historical evidence is left of the progenitors and prophets of these faiths. Those that came after are much more recent – starting with Islam in 700 A.D. – and the fact that the father figures of these religions are historically verifiable is paradoxically a liability to the religion. Without an aura of miraculousness, these religions have a weaker ability to compel us to suspend our disbelief.

Being children of the Enlightenment, we naturally do not believe in the miraculous origins and stories of Christianity. However, this doesn’t take away from the near-certainty that Christ and his followers were real historical figures, not least because the origins of Christianity clearly took place in reaction to the practices of an established religious community – the Jews – whose traditions are still largely preserved from that era. The continuity of the Jewish tradition from ancient times to today in themselves form a guarantee of the historical truth of the story of Christ.

What makes the narrative of Christianity even more compelling and interesting is the variety of forms it has taken over the years. In understanding these forms and how they came about, we learn not only about Christians, but about the progress of much of human thought in the two millennia that have succeeded Christ.

Christianity’s development closely parallels the development of European thought. Studying the development of Christianity is of interest to any observer of European societies, and by extension of those of the New World. Christian thought has also been an integral part of the development of Western philosophy – or at least one can say, most Western philosophers prior to the twentieth century have been students of Christian theology. The ideas that form the Christian faith therefore have contributed widely to the development of the philosophical thought that has been a major contributor to philosophical and political discourse in modern times.

There are of course many published histories of Christianity, and this history can hardly compare in scope and scholarly heft. The aim of this history is to be a simple but exciting narrative, and a navigational guide to someone trying to understand how Christianity originated and how its various flavors have taken shape over the last two millennia. This history will also pay a great deal of attention to the intellectual conflicts that led to divisions in the faith and its component churches, because these conflicts, which might have been incidental and academic when they first arose, generated, either immediately or over the course of many decades and centuries, some of the most far-reaching divides and conflicts in human history. Starting outwards from the quarrels between two ancient Mediterranean or two medieval European monasteries, and traveling through the magnifying effects of the spread of European power through the world, minute differences in arcane theological and social matters have now affected billions of lives. The aim of this history is to help the reader follow along the path that some of those developments have taken.

Right from its beginning, Christianity has also been a political religion. The faith has driven the course of many monarchs and soldiers, but it has also been pulled apart by the ambition of these rulers in turn. The conviction of its followers has been channeled and exploited by many political elites over the years to gain political legitimacy and to rally their troops to wage war. Behind many denominational categories, like Anglicanism, Protestantism, Baptism, and the Orthodox creeds, lie complex and bloody histories. This history will try to outline the most major and influential of these battles in order to give the reader a better sense of why Christianity’s various sects have arisen and what divides them so deeply even though they hold fundamental beliefs that unite all Christians, separating them so vividly from the other faiths of the world.