The present work constitutes a necessary and clarifying contribution to offer a deeper and more nuanced vision of Christianity, the common foundation of all Western civilization. In the field of Western history there are moments and places characterized by a special cultural or religious intensity that have indelibly marked the development of their subsequent social life. One of them was the Eastern Mediterranean in the centuries before and after the birth of Christianity, one of the great worldviews that is an intrinsic part of the history of humanity and whose consequences we still perceive today. But in the field of history, no event is fully known unless its roots and conditioning are studied first. In this sense, the book that the reader has in his hands is a detailed study of the origins of Christianity from academic rigor and thoroughness. Origins of Christianity is a work of collaboration with Jewish and Christian specialists of various confessions and independent researchers who They present their ideas and reflections on the subject and contribute with their contributions -some of them, as the wise reader will observe, very original- to a deeper and more complex vision of Christianity.