The Christian Church is a term used by some to refer to the whole group of people belonging to the Christian religious tradition throughout history. With “Church” capitalized, the term does not refer to a building. Others believe the term “Christian Church” or “Church” applies only to a specific historic Christian institution (e.g., the Catholic Church, the Eastern Orthodox Church, and Oriental Orthodoxy). The term Christian Church, in the first understanding, which is generally used by Protestants, does not refer to a particular denomination. However, the majority of Christians belong to groups that consider themselves to be the one true church, to which other Christians do not belong. The three largest such groups are the Catholic Church, the Eastern Orthodox Church, and the Oriental Orthodox communion. Thus, some Christians identify the Christian Church with a visible structure (the view of the Catholic, Eastern Orthodox, and Oriental Orthodox churches) while others (generally Protestants) understand it as an invisible reality not identified with any earthly structure and others equate it with particular groups that share certain essential elements of doctrine and practice though divided on other points of doctrine and government (such as the branch theory as taught by some Anglicans). The Greek term ἐκκλησία, which is transliterated as “ecclesia”, generally meant an “assembly”, but in most English translations of the New Testament is usually translated as “church”. This term appears in two verses of the Gospel of Matthew, twenty-four verses of the Acts of the Apostles, fifty-eight verses of the Pauline Epistles (including the earliest instances of its use in relation to a Christian body), two verses of the Letter to the Hebrews, one verse of the Epistle of James, three verses of the Third Epistle of John, and nineteen verses of the Book of Revelation. In total, ἐκκλησία appears in the New Testament text 114 times, although not every instance is a technical reference to the church. In the New Testament, the term ἐκκλησία is used for local communities as well as in a universal sense to mean all believers. Traditionally, only orthodox believers are considered part of the true church, but convictions of what is orthodox have long varied, as many churches (not only the ones officially using the term “Orthodox” in their names) consider themselves to be orthodox and other Christians to be heterodox. The Four Marks of the Church first expressed in the Nicene Creed are unity, holiness, catholicity, and apostolicity.