Complex sentence: The Orthodox Church traces its history to the church established by St. Paul and the Apostles, through the Roman and Byzantine Empires, and regards itself as the original Church founded by Christ and His apostles.
Split into simpler sentences: The Orthodox Church traces its development back to the earliest church established by St. Paul and the Apostles, through the ancient Roman Empire and its continuation the Byzantine Empire. It regards itself as the historical and organic continuation of the original Church founded by Christ and His apostles.