Icon in the context of "Divine Liturgy"

The Eastern Orthodox Church, officially the Orthodox Catholic Church, and also called the Greek Orthodox Church or simply the Orthodox Church, is one of the three major doctrinal and jurisdictional groups of Christianity. As of 2012, it has approximately 300 million adherents and is the third largest religious community in the world after Catholics and Sunni Muslims. The Eastern Orthodox Church operates as a communion of autocephalous churches, each governed by its bishops via local synods. The church has no central doctrinal or governmental authority analogous to the pope of the Catholic Church. Nevertheless, the Ecumenical Patriarch of Constantinople is recognised by them as primus inter pares ('first among equals'), a title held by the patriarch of Rome prior to 1054. As one of the oldest surviving religious institutions in the world, the Eastern Orthodox Church has played an especially prominent role in the history and culture of Eastern and Southeastern Europe. Since 2018, there has been an ongoing schism between Constantinople and Moscow, with the two not in full communion with each other.

Eastern Orthodox theology is based on the Scriptures and holy tradition, which incorporates the dogmatic decrees of the seven ecumenical councils, and the teaching of the Church Fathers. The church teaches that it is the one, holy, catholic and apostolic church established by Jesus Christ in his Great Commission, and that its bishops are the successors of Christ's apostles. It maintains that it practises the original Christian faith, as passed down by holy tradition. Its patriarchates, descending from the pentarchy, and other autocephalous and autonomous churches, reflect a variety of hierarchical organisation. It recognises seven major sacraments (which are called holy mysteries), of which the Eucharist is the principal one, celebrated liturgically in synaxis. The church teaches that through consecration invoked by a priest, the sacrificial bread and wine become the body and blood of Christ. The Virgin Mary is venerated in the Eastern Orthodox Church as the Theotokos, which means 'God-bearer', and she is honoured in devotions.

Christ Pantocrator of Saint Catherine's Monastery is one of the oldest Byzantine religious icons, dating from the 6th century AD. The earliest known surviving depiction of Jesus Christ as Pantocrator (literally ruler of all), it is regarded by historians and scholars among the most important and recognizable works in the study of Byzantine art as well as Eastern Orthodox and Eastern Catholic Christianity.

A synaxis (Greek: σύναξις "gathering"; Slavonic: собор, sobor) is a liturgical assembly in Eastern Christianity (the Eastern Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite).

Marian devotions are external pious practices directed to the person of Mary, mother of Jesus, by members of certain Christian traditions. They are performed in Catholicism, High Church Lutheranism, Anglo-Catholicism, Eastern Orthodoxy and Oriental Orthodoxy, but other Christian denominations mostly reject them.

Such devotional prayers may be accompanied by specific requests for Mary's intercession with God. There is significant diversity of form and structure in Marian devotions practiced by different groups of Christians. Orthodox Marian devotions are well-defined and closely linked to liturgy, while Roman Catholic practices are wide-ranging—they include multi-day prayers such as novenas, the celebration of canonical coronations granted by the Pope, the veneration of icons in Eastern Christianity, and pious acts which do not involve vocal prayers, such as the wearing of scapulars or maintaining a Mary garden.

Oil painting is a painting method involving the procedure of painting with pigments combined with a drying oil as the binder. It has been the most common technique for artistic painting on canvas, wood panel, or copper for several centuries. The advantages of oil for painting images include "greater flexibility, richer and denser color, the use of layers, and a wider range from light to dark".

The oldest known oil paintings were created by Buddhist artists in Afghanistan, and date back to the 7th century AD. Oil paint was later developed by Europeans for painting statues and woodwork from at least the 12th century, but its common use for painted images began with Early Netherlandish painting in Northern Europe, and by the height of the Renaissance, oil painting techniques had almost completely replaced the use of egg tempera paints for panel paintings in most of Europe, though not for Orthodox icons or wall paintings, where tempera and fresco, respectively, remained the usual choice.

Nicene Christianity includes those Christian denominations that adhere to the teaching of the Nicene Creed, which was formulated at the First Council of Nicaea in AD 325 and amended at the First Council of Constantinople in AD 381. It encompasses the vast majority of today's Christian churches.

Christ, used by Christians as both a name and a title, unambiguously refers to Jesus. As a title it is used both in the reciprocal form "Christ Jesus", meaning "the Messiah Jesus" (or "Jesus the Khristós"; lit. "Jesus the Anointed"), and independently as "the Christ". The earliest texts of the New Testament, the Pauline epistles, often refer to Jesus as "Christ Jesus", or simply "Christ".

The concept of the Christ in Christianity originated from the concept of the messiah in Judaism. Christians believe that Jesus is the messiah foretold in the Hebrew Bible and the Christian Old Testament. Although the conceptions of the messiah in each religion are similar, for the most part they are distinct from one another due to the split of early Christianity and Judaism in the 1st century.

The Nicene Creed, also called the Creed of Constantinople, is the defining statement of belief of Nicene Christianity and in those Christian denominations that adhere to it.

The original Nicene Creed was first adopted at the First Council of Nicaea in 325. According to the traditional view, forwarded by the Council of Chalcedon of 451, the Creed was amended in 381 by the First Council of Constantinople as "consonant to the holy and great Synod of Nice." However, many scholars comment on these ancient Councils, saying "there is a failure of evidence" for this position since no one between the years of 381–451 thought of it in this light. Further, a creed "almost identical in form" was used as early as 374 by St. Epiphanius of Salamis. Nonetheless, the amended form is presently referred to as the Nicene Creed or the Niceno-Constantinopolitan Creed.