Papal primacyPapal primacy, also known as the primacy of the bishop of Rome, is a ecclesiological doctrine in the Catholic Church concerning the respect and authority that is due to the pope from other bishops and their episcopal sees. While the doctrine is accepted at a fundamental level by both the Catholic Church and Eastern Orthodox Church, the two disagree on the nature of primacy. English academic and Catholic priest Aidan Nichols wrote that "at root, only one issue of substance divides the Eastern Orthodox and the Catholic Churches, and that is the issue of the primacy.
DiptychA diptych (ˈdɪptɪk; from the Greek δίπτυχον, di "two" + ptychē "fold") is any object with two flat plates which form a pair, often attached by hinge. For example, the standard notebook and school exercise book of the ancient world was a diptych consisting of a pair of such plates that contained a recessed space filled with wax. Writing was accomplished by scratching the wax surface with a stylus. When the notes were no longer needed, the wax could be slightly heated and then smoothed to allow reuse.
Open communionOpen communion is the practice of some Protestant Churches of allowing members and non-members to receive the Eucharist (also called Holy Communion or the Lord's Supper). Many but not all churches that practice open communion require that the person receiving communion be a baptized Christian, and other requirements may apply as well. In Methodism, open communion is referred to as the open table, meaning that all may approach the Communion table.
CatholicosA catholicos (plural: catholicoi) is the head of certain churches in some Eastern Christian traditions. The title implies autocephaly and, in some cases, it is the title of the head of an autonomous church. The word comes from ancient Greek καθολικός ( () καθολικοί), derived from καθ' ὅλου (, "generally") from κατά (, "down") and ὅλος (, "whole"), meaning "concerning the whole, universal, general"; it originally designated a financial or civil office in the Roman Empire.
MiaphysitismMiaphysitism is the Christological doctrine that holds Jesus, the "Incarnate Word, is fully divine and fully human, in one 'nature' (physis)." It is a position held by the Oriental Orthodox Churches and differs from the Chalcedonian position that Jesus is one "person" (ὑπόστασις) in two "natures" (φύσεις), a divine nature and a human nature (Dyophysitism). While historically a major point of controversy within Christianity, several modern declarations by both Chalcedonian and Miaphysite churches state that the difference between the two Christological formulations does not reflect any significant difference in belief about the nature of Christ.
KoinoniaKoinonia (ˌkɔɪnoʊˈniːə) is a transliterated form of the Greek word κοινωνία, which refers to concepts such as fellowship, joint participation, partnership, the share which one has in anything, a gift jointly contributed, a collection, a contribution. In the Politics of Aristotle it is used to mean a community of any size from a single family to a polis. As a polis, it is the Greek for republic or commonwealth. In later Christianity it identifies the idealized state of fellowship and unity that should exist within the Christian church, the Body of Christ.
Ancient Church of the EastThe Ancient Church of the East is an Eastern Christian denomination. It branched from the Assyrian Church of the East in 1964, under the leadership of Mar Toma Darmo (d. 1969). It is one of three Assyrian Churches that claim continuity with the historical Church of the East (the ancient Patriarchal Province of Seleucia-Ctesiphon), the others being the Assyrian Church of the East and the Chaldean Catholic Church. Since 1969, the see of the Ancient Church of the East is headquartered in Baghdad.
Catechism of the Catholic ChurchThe Catechism of the Catholic Church (Catechismus Catholicae Ecclesiae; commonly called the Catechism or the CCC) is a reference work that summarizes the Catholic Church's doctrine. It was promulgated by Pope John Paul II in 1992 as a reference for the development of local catechisms, directed primarily to those (in the Church) responsible for catechesis and offered as "useful reading for all other Christian faithful". It has been translated into and published in more than twenty languages worldwide.
Sui iurisSui iuris (ˈsu:aɪ_ˈdʒʊərɪs or ˈsu:i_ˈjurɪs) also spelled sui juris, is a Latin phrase that literally means "of one's own right". It is used in both secular law and the Catholic Church's canon law. The term church sui iuris is used in the Catholic Code of Canons of the Eastern Churches (CCEO) to denote the autonomous churches in Catholic communion. The Catholic Church consists of 24 churches, including the Latin Church and 23 Eastern Catholic churches.
Closed communionClosed communion is the practice of restricting the serving of the elements of Holy Communion (also called Eucharist, The Lord's Supper) to those who are members in good standing of a particular church, denomination, sect, or congregation. Though the meaning of the term varies slightly in different Christian theological traditions, it generally means that a church or denomination limits participation (with respect to the Eucharist) either to members of their own church, members of their own denomination, or members of some specific class (e.
