A profound reflection and interpretation of the history of Eastern Christianity, this work serves as a highly respected introduction for anyone wishing to understand the Orthodox Church, both Orthodox and non-Orthodox. Schmemann emphasizes that his book is not a dry academic research or a mere chronology of events. Rather, it is a historical pilgrimage. The author invites readers to reflect on the long journey of the Orthodox Church, distinguishing which values are essential (permanent) from which traditions are merely "past." The book's main focus is how Orthodoxy maintains the purity of the apostolic faith amidst the changing times, explaining how Eastern Christianity underwent a long transformation from the early Church and the Byzantine Empire to the expansion and challenges of the modern world, and providing an interpretation and critique of the concept of symphony (the close relationship between church and state in the Byzantine era) and its impact on countries such as Bulgaria and Russia. Schmemann hopes that through this book, Western Christians will realize that the history of Eastern Christianity is fundamentally their shared roots and past.