There is only one religion, though there are a hundred versions of it.
George Bernard Shaw, Plays Pleasant and Unpleasant, Vol. II, preface (1898)
The adjective ‘Orthodox’ translates as ‘correct belief’. Included in this are Orthodoxy Christianity’s four traditions: Eastern (Chalcedonian), Oriental (Pre-Chalcedonian, Non-Chalcedonian, Monophysite), Nestorian (Assyrian), and non-historical Orthodox. (Information source: World Christian Database)