John Chrysostom (c. 347–407, Greek: Ἰωάννης ὁ Χρυσόστομος), Archbishop of Constantinople, was an important Early Church Father. He is known for his eloquence in preaching and public speaking, his denunciation of abuse of authority by both ecclesiastical and political leaders, the Divine Liturgy of St. John Chrysostom, and his ascetic sensibilities. After his death in 407 (or, according to some sources, during his life) he was given the Greek epithet chrysostomos, meaning "golden mouthed", in English and Anglicized to Chrysostom. The Orthodox and Eastern Catholic Churches honor him as a saint and count him among the Three Holy Hierarchs, together with Basil the Great and Gregory Nazianzus. He is recognized by the Eastern Orthodox Church and the Catholic Church as a saint and as a Doctor of the Church. Churches of the Western tradition, including the Roman Catholic Church, some Anglican provinces, and parts of the Lutheran Church, commemorate him on 13 September. Some Lutheran and many Anglican provinces commemorate him on the traditional Eastern feast day of 27 January. The Coptic Orthodox Church of Alexandria also recognizes John Chrysostom as a saint (with feast days on 16 Thout and 17 Hathor). John is known in Christianity chiefly as a preacher, theologian and liturgist. Among his homilies, eight directed against Judaizing Christians remain controversial for their impact on the development of Christian antisemitism.

Nicholas Cabasilas (Greek: Νικόλαος Καβάσιλας; born 1319/1323 in Thessalonica; died 1392) was a Byzantine mystic and theological writer. Cabasilas is a saint within the Orthodox Church. His feast day is June 20. The Roman Catholic Church uses extracts from his Life in Christ as readings in the Liturgy of the Hours (Tuesday, Wednesday, and Thursday of the Fifth Week of Easter in Year II of the two-year cycle for the Office of Readings). He was on intimate terms with the emperor John VI Cantacuzene, whom he accompanied in his retirement to a monastery. He was once thought to have succeeded his uncle Nilus Cabasilas as archbishop of Thessalonica; however contemporary records of that see do not show Nicholas as serving in the capacity of archbishop. It is more likely that he served as a priest at the Manganon monastery near Constantinople. In the Hesychast controversy he took the side of the monks of Mount Athos and Saint Gregory Palamas. His chief work is his Περὶ τῆς ἐν Χριστῷ ζωῆς, ("On the Life in Christ"). in which he lays down the principle that union with Christ is effected by the three great mysteries of baptism, chrismation, and the eucharist. He also wrote homilies on various subjects, and a speech against usurers, printed with other works in Migne, Patrologia Graeca, c. i. A large number of his works is still extant in manuscript. Cabasilas' major works are Life in Christ and Commentary on the Divine Liturgy. These works display a profound understanding of the sacramental and liturgical life of the Eastern Orthodox Church and are accessible to and instructive for any Christian today worshiping in either the East or West.

St. Theophan the Recluse, also known as Theophan Zatvornik or Theophanes the Recluse (Russian: Феофан Затворник), is a well-known saint in the Russian Orthodox Church. He was born George Vasilievich Govorov, in the village of Chernavsk. His father was a Russian Orthodox priest. He was educated in the seminaries at Livny, Orel and Kiev. In 1841 he was ordained, became a monk, and adopted the name Theophan. He later became the Bishop of Tambov. He is especially well-known today through the many books he wrote concerning the spiritual life, especially on the subjects of the Christian life and the training of youth in the faith. He also played an important role in translating the Philokalia from Church Slavonic into Russian. The Philokalia is a classic of orthodox spirituality, composed of the collected works of a number of church fathers which were edited and placed in a four volume set in the 17th and 18th centuries. A persistent theme is developing an interior life of continuous prayer, learning to "pray without ceasing" as St. Paul teaches in his first letter to the Thessalonians. Russian profile: Феофан Затворник

Dymytrii Tuptalo (Rostovsky) (secular name: Danylo) - Saint, writer, theologian, and churchman. He studied at the Kyivan Mohyla Academy in 1662–5 and entered Saint Cyril's Monastery in Kyiv in 1668. In 1675 he was ordained a hieromonk by Archbishop Lazar Baranovych. During the next 30 years he was hegumen of several Ukrainian monasteries (the Hustynia Trinity Monastery, Trinity–Saint Elijah's Monastery, the Yeletskyi Dormition Monastery, Saint Nicholas' Monastery in Baturyn, the Novodvirske Monastery in Volhynia, the Kyivan Cave Monastery) and Belarusian monasteries (Vilnius and Slutsk). In 1701 Tsar Peter I summoned him to Moscow, where he was consecrated metropolitan on 23 March 1701. He was assigned to the Tobolsk see but did not assume the post because of ill health. Instead, in 1702 he was sent to Rostov. Tuptalo was associated with a group of Ukrainian hierarchs in the Russian church, led by Metropolitan Stefan Yavorsky, who fought against the Old Believers and other sects that had left the church over reforms introduced under Tsar Aleksei Mikhailovich. This group, however, did not accept the more radical changes favored by Peter, especially the subordination of the church to the state. Tuptalo's first published work was Runo oroshennoie (The Bedewed Fleece, 1680; 7 edns by 1702), a collection of stories about miracles attributed to the icon of the Mother of God at the Chernihiv Trinity–Saint Elijah's Monastery. His most important work is his menaion for daily reading, a major collection of the lives of saints. It was first published by the Kyivan Cave Monastery in 1689–1705; at least 10 more editions followed in the 18th century. This collection is the best example of Ukrainian hagiography of the 17th and 18th centuries; it contains the lives of many early Ukrainian saints, based on various manuscripts and on adaptations from Greek and Latin sources. Tuptalo was a well-known orator, and a collection of his sermons (some of which criticized the reforms of Peter I), edited by A. Titov, appeared in 1909. He also wrote polemical attacks (see Polemical literature) on the schism (Rozysk o raskolnicheskoi brynskoi vere [An Examination of the Schismatic Brynian Sect, 1709]), theological treatises (Zertsalo pravoslavnogo ispovedaniia [The Mirror of the Orthodox Faith, 1805]), and historical studies (Letopis’ izhe vo sviatykh ... ot nachala mirobytiia do Rozhdestva Khristova [The Chronicle of Saints ... from the Beginning of Life on Earth to the Birth of Christ, 1784]). His literary works—including the spiritual dramas Komediia na den’ Rozhdestva Khristova (A Comedy on the Day of Christ's Birth) and Uspenie Bohorodytsi (The Dormition of the Mother of God)—were baroque in style and influenced by Western writing. The language Tuptalo used in his theological works was Old Church Slavonic, but it contained many Ukrainianisms. His sermons and menaion, which were intended for a popular audience, were close to the vernacular; posthumous editions of the menaion, however, were Russified by order of the Holy Synod.