Catholic Church

Rome is the capital city and most populated comune (municipality) of Italy. It is also the administrative centre of the Lazio region and of the Metropolitan City of Rome. A special comune named Roma Capitale with 2,746,984 residents in 1,287.36 km (497.1 sq mi), Rome is the third most populous city in the European Union by population within city limits. The Metropolitan City of Rome Capital, with a population of 4,223,885 residents, is the most populous metropolitan city in Italy. Its metropolitan area is the third-most populous within Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber Valley. Vatican City (the smallest country in the world and headquarters of the worldwide Catholic Church under the governance of the Holy See) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city. Rome is often referred to as the City of Seven Hills due to its geography, and also as the "Eternal City". Rome is generally considered to be one of the cradles of Western civilization and Western Christian culture, and the centre of the Catholic Church.

Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it a major human settlement for over three millennia and one of the oldest continuously occupied cities in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded by many as the first-ever Imperial city and metropolis. It was first called The Eternal City (Latin: Urbs Aeterna; Italian: La Città Eterna) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called Caput Mundi (Capital of the World).

A state religion (also called official religion) is a religion or creed officially endorsed by a sovereign state. A state with an official religion (also known as a confessional state), while not a secular state, is not necessarily a theocracy. State religions are subject to advantageous treatment by official or government-sanctioned establishments of them, ranging from incentivising citizens to recognise and practice them through government endorsement to having public spending on the maintenance of religious property and clergy be unrestricted, but the state does not need to be under the legislative control of the clergy as it would be in a theocracy. Generally, these religions have more rights and fewer restrictions in the country than other religions in a country.

Official religions have been known throughout human history in almost all types of cultures, reaching into the Ancient Near East and prehistory. The relation of religious cult and the state was discussed by the ancient Latin scholar Marcus Terentius Varro, under the term of theologia civilis (lit. 'civic theology'). The first state-sponsored Christian denomination was the Armenian Apostolic Church, established in 301 CE. In Christianity, as the term church is typically applied to a place of worship for Christians or organizations incorporating such ones, the term state church is associated with Christianity as sanctioned by the government, historically the state church of the Roman Empire in the last centuries of the Empire's existence, and is sometimes used to denote a specific modern national branch of Christianity. Closely related to state churches are ecclesiae, which are similar but carry a more minor connotation.

Eastern Orthodoxy, otherwise known as Eastern Orthodox Christianity or Byzantine Christianity, is one of the three main branches of Chalcedonian Christianity, alongside Catholicism and Protestantism. Like the Pentarchy of the first millennium, the mainstream (or "canonical") Eastern Orthodox Church is organised into autocephalous churches independent from each other. In the 21st century, the number of mainstream autocephalous churches is seventeen; there also exist autocephalous churches unrecognized by those mainstream ones. Autocephalous churches choose their own primate. Autocephalous churches can have jurisdiction (authority) over other churches, some of which have the status of "autonomous" which means they have more autonomy than simple eparchies.

Many of these jurisdictions correspond to the territories of one or more modern states; the Patriarchate of Moscow, for example, corresponds to Russia and some of the other post-Soviet states. They can also include metropolises, bishoprics, parishes, monasteries, or outlying metochia corresponding to diasporas that can also be located outside the country where the primate resides (e.g., the case of the Ecumenical Patriarchate of Constantinople whose canonical territory is located partly in northern Greece and the east); sometimes they overlap (the case of Moldova where the jurisdictions of the patriarchs of Bucharest and of Moscow overlap).

A sacred language, liturgical language or holy language is a language that is cultivated and used primarily for religious reasons (like church service) by people who speak another, primary language in their daily lives.

Some religions, or parts of them, regard the language of their sacred texts as in itself sacred. These include Ecclesiastical Latin in Roman Catholicism, Hebrew in Judaism, Arabic in Islam, Avestan in Zoroastrianism, Sanskrit in Hinduism, and Punjabi in Sikhism. By contrast Buddhism and Christian denominations outside of Catholicism do not generally regard their sacred languages as sacred in themselves.

An icon (from Ancient Greek εἰκών (eikṓn) 'image, resemblance') is a religious work of art, most commonly a painting, in the cultures of the Eastern Orthodox, Oriental Orthodox, Catholic, and Lutheran churches. The most common subjects include Jesus, Mary, saints, and angels. Although especially associated with portrait-style images concentrating on one or two main figures, the term also covers most of the religious images in a variety of artistic media produced by Eastern Christianity, including narrative scenes, usually from the Bible or the lives of saints.

Icons are most commonly painted on wood panels with egg tempera, but they may also be cast in metal or carved in stone or embroidered on cloth or done in mosaic or fresco work or printed on paper or metal, etc. Comparable images from Western Christianity may be classified as "icons", although "iconic" may also be used to describe the static style of a devotional image. In the Greek language, the term for icon painting uses the same word as for "writing", and Orthodox sources often translate it into English as icon writing.

The pope is the bishop of Rome and the head of the worldwide Catholic Church. He is also known as the supreme pontiff, Roman pontiff, or sovereign pontiff. From the 8th century until 1870, the pope was the sovereign or head of state of the Papal States, and since 1929 of the much smaller Vatican City State. From a Catholic viewpoint, the primacy of the bishop of Rome is largely derived from his role as the apostolic successor to Saint Peter, to whom primacy was conferred by Jesus, who gave Peter the Keys of Heaven and the powers of "binding and loosing", naming him as the "rock" upon which the Church would be built. The current pope is Leo XIV, who was elected on 8 May 2025 on the second day of the 2025 papal conclave.

While his office is called the papacy, the jurisdiction of the episcopal see is called the Holy See. The word see comes from the Latin for 'seat' or 'chair' (sede, referring in particular to the one on which the newly elected pope sits during the enthronement ceremony). The Holy See is a sovereign entity under international law; it is headquartered in the distinctively independent Vatican City, a city-state which forms a geographical enclave within the conurbation of Rome. It was established by the Lateran Treaty in 1929 between Fascist Italy and the Holy See to ensure its political and spiritual independence. The Holy See is recognized by its adherence at various levels to international organizations and by means of its diplomatic relations and political accords with many independent states.

The Four Marks of the Church, also known as the Attributes of the Church, describes four distinctive adjectives of traditional Christian ecclesiology as expressed in the Nicene Creed completed at the First Council of Constantinople in AD 381: "[We believe] in one, holy, catholic, and apostolic Church."

This ecumenical creed is today recited in the liturgies of the Eastern Orthodox Church, the Catholic Church (both Latin and Eastern Rites), the Oriental Orthodox Churches, the Assyrian Church of the East, the Moravian Church, the Lutheran Churches, the Methodist Churches, the Presbyterian Churches, the Anglican Communion, and by members of the Reformed Churches, although they interpret it in very different ways, and some Protestants alter the word "Catholic" in the creed, replacing it with the word "Christian".

The expression "one true church" refers to an ecclesiological position asserting that Jesus gave his authority in the Great Commission solely to a particular visible Christian institutional church—what is commonly called a denomination. This view is maintained by the Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox communion, the Assyrian Church of the East, the Ancient Church of the East, and the Lutheran churches, as well as certain Baptists. Each of them maintains that their own specific institutional church (denomination) exclusively represents the one and only original church. The claim to the title of the "one true church" relates to the first of the Four Marks of the Church mentioned in the Nicene Creed: "one, holy, catholic, and apostolic church". As such, it also relates to claims of both catholicity and apostolic succession: asserting inheritance of the spiritual, ecclesiastical and sacramental authority and responsibility that Jesus Christ gave to the apostles.

The concept of schism somewhat moderates the competing claims between some churches—one can potentially repair schism, since they are striving for the same goal. For example, the Catholic and Eastern Orthodox churches each regard the other as schismatic and at very least heterodox, if not heretical, yet both have held dialogues and even partaken in Councils in attempts to resolve the division that exists between them.

Apostolic succession is the method whereby the ministry of the Christian Church is considered by some Christian denominations to be derived from the apostles by a continuous succession, which has usually been associated with a claim that the succession is through a series of bishops. Those of the Catholic, Eastern Orthodox, Oriental Orthodox, Church of the East traditions maintain that a bishop's orders are neither regular nor valid without consecration through apostolic succession. These traditions do not always consider the episcopal consecrations of all of the other traditions as valid.

This series was seen originally as that of the bishops of a particular see founded by one or more of the apostles. According to historian Justo L. González, apostolic succession is generally understood today as meaning a series of bishops, regardless of see, each consecrated by other bishops, themselves consecrated similarly in a succession going back to the apostles. According to the Joint International Commission for Theological Dialogue Between the Catholic Church and the Orthodox Church, "apostolic succession" means more than a mere transmission of powers. It is succession in a church which witnesses to the apostolic faith, in communion with the other churches, witnesses of the same apostolic faith. The "see (cathedra) plays an important role in inserting the bishop into the heart of ecclesial apostolicity", but once ordained, the bishop becomes in his church the guarantor of apostolicity and becomes a successor of the apostles.

A sacrament is a Christian rite which is recognized as being particularly important and significant. There are various views on the existence, number and meaning of such rites. Many Christians consider the sacraments to be a visible symbol of the reality of God, as well as a channel for God's grace. Many denominations, including the Catholic, Lutheran, Moravian, Reformed (Continental Reformed, Presbyterian, and Congregationalist traditions), Anglican, Methodist and Baptist, hold to the definition of sacrament formulated by Augustine of Hippo: an outward sign of an inward grace, that has been instituted by Jesus Christ. Sacraments signify God's grace in a way that is outwardly observable to the participant.

The Catholic Church, Hussite Church and the Old Catholic Church recognize seven sacraments: Baptism, Penance (Reconciliation or Confession), Eucharist (or Holy Communion), Confirmation, Marriage (Matrimony), Holy Orders, and Anointing of the Sick (Extreme Unction). The Eastern Churches, such as the Eastern Orthodox Church and Oriental Orthodox Church as well as the Eastern Catholic Churches, recognize these as the seven major sacraments, but also apply the words sacred mysteries corresponding to Greek word, μυστήριον (mysterion), and also to rites that in the Western tradition are called sacramentals and to other realities, such as the Church itself. Many Protestant denominations, such as those within the Reformed tradition, preach just two sacraments instituted by Christ: the Eucharist (or Holy Communion) and Baptism. The Lutheran sacraments include these two, often adding Confession (and Absolution) as a third sacrament. Anglican and Methodist teaching is that "there are two Sacraments ordained of Christ our Lord in the Gospel, that is to say, Baptism and the Supper of the Lord", and that "those five commonly called Sacraments, that is to say, Confirmation, Penance, Orders, Matrimony, and Extreme Unction, are not to be counted for Sacraments of the Gospel."