Gregory of Nazianzus in the context of "Three Holy Hierarchs"

John Chrysostom (/ˈkrɪsəstəm, krɪˈsɒstəm/; Greek: Ἰωάννης ὁ Χρυσόστομος, Latin: Ioannes Chrysostomus; c. 347 – 14 September 407) was an important Church Father who served as Archbishop of Constantinople. He is known for his preaching and public speaking, his denunciation of abuse of authority by both ecclesiastical and political leaders, his Divine Liturgy of Saint John Chrysostom, and his ascetic sensibilities. He was also the author of Adversus Judaeos and was strongly against Judaism. The epithet Χρυσόστομος (Chrysostomos, anglicized as Chrysostom) means "golden-mouthed" in Greek and denotes his celebrated eloquence. Chrysostom was among the most prolific authors in the early Christian Church.

He is honored as a saint in the Eastern Orthodox, Oriental Orthodox, Catholic, Anglican, and Lutheran churches, as well as in some others. The Eastern Orthodox, together with the Byzantine Catholics, hold him in special regard as one of the Three Holy Hierarchs (alongside Basil of Caesarea and Gregory of Nazianzus). Along with them and Athanasius of Alexandria he is also regarded as one of the four Great Greek Church Fathers. The feast days of John Chrysostom in the Eastern Orthodox Church are 14 September, 13 November and 27 January. In the Catholic Church, he is recognised as a Doctor of the Church. Because the date of his death is occupied by the feast of the Exaltation of the Holy Cross (14 September), the General Roman Calendar celebrates him since 1970 on the previous day, 13 September; from the 13th century to 1969 it did so on 27 January, the anniversary of the translation of his body to Constantinople. Of other Western churches, including Anglican provinces and Lutheran churches, some commemorate him on 13 September, others on 27 January. John Chrysostom is honored on the calendars of the Church of England and the Episcopal Church on 13 September. The Coptic Church also recognizes him as a saint (with feast days on 16 Thout and 17 Hathor).

The Orthodox Cathedral (Romanian: Catedrala Ortodoxă), also known as the Metropolitan Cathedral (Romanian: Catedrala Mitropolitană), is a Romanian Orthodox church in Timișoara. The cathedral is the seat of the Archbishopric of Timișoara and the Metropolis of Banat. It is dedicated to the Three Holy Hierarchs, Basil the Great, Gregory the Theologian and John Chrysostom.

Built on an area of 1,542 m, it has 11 towers, of which the central one has a height of 90.5 m, making it the second tallest church in Romania, after the People's Salvation Cathedral in Bucharest. The cathedral is listed in the National Register of Historic Monuments.

The Alexandrian rites are a collection of ritual families and uses of Christian liturgy employed by three Oriental Orthodox churches (the Coptic Orthodox Church, the Eritrean Orthodox Tewahedo Church, and the Ethiopian Orthodox Tewahedo Church), and by three Eastern Catholic Churches (the Coptic Catholic Church, the Eritrean Catholic Church, and the Ethiopian Catholic Church).

The Alexandrian rite's Divine Liturgy contains elements from the liturgies of Saints Mark the Evangelist (who is traditionally regarded as the first bishop of Alexandria), Basil the Great, Cyril of Alexandria, and Gregory of Nazianzus. The Alexandrian rites are sub-grouped into two rites: the Coptic Rite and the Ge'ez Rite.

Neoplatonism was a major influence on Christian theology throughout Late Antiquity and the Middle Ages in the East, and sometimes in the West as well. In the East, major Greek Fathers like Basil, Gregory of Nyssa and Gregory of Nazianzus were influenced by Platonism and Neoplatonism, but also Stoicism often leading towards asceticism and harsh treatment of the body, for example stylite asceticism. In the West, St. Augustine of Hippo was influenced by the early Neoplatonists Plotinus and Porphyry. Later on, in the East, the works of the Christian writer Pseudo-Dionysius the Areopagite, who was influenced by later Neoplatonists such as Proclus and Damascius, became a critical work on which Greek church fathers based their theology, like Maximus believing it was an original work of Dionysius the Areopagite.

Euzoius of Caesarea (Greek: Ευζώιος, romanized: Euzōios; fl. AD 373–379) was a Christian theologian and bishop of the 4th century.

In Jerome's De viris illustribus, he writes that Euzoius was educated alongside Gregory of Nazianzus by "Thespesius the rhetorician" at Caesarea Maritima. In 373 Euzoius became Bishop of Caesarea and he worked to restore its library, copying many papyrus works to parchment. He was expelled from the church during the reign of Theodosius I (r. 379–395). He wrote several treatises, none of which survives.

In Christian theology, perichoresis (from Ancient Greek: περιχώρησις, romanized: perikhōrēsis, lit. 'rotation') is the relationship of the three persons of the triune God (Father, Son, and Holy Spirit) to one another. The term was first used theologically by the Church Fathers. As a noun, the word first appears in the writings of Maximus Confessor (d. 662), but the related verb perichoreo is found earlier in the work of Gregory of Nazianzus (d. 389/90). Gregory used the word to describe the relationship between the divine and human natures of Christ, as did John of Damascus (d. 749), who also extended it to the "interpenetration" of the three persons of the Trinity, and it became a technical term for the latter. "Circumincession" is a Latin-derived term for the same concept. However, the idea was present in Latin Christianity even before the Eastern fathers; this is made explicit by St. Hillary's De Trinitate. Augustine also writes in his De Trinitate (On the Trinity):

The term has been given recent currency by such contemporary writers as Jürgen Moltmann, Miroslav Volf, John Zizioulas, Richard Rohr, and others. Modern authors extend the original usage as an analogy to cover other interpersonal relationships. The term "co(-)inherence" is sometimes used as a synonym.