Righteous Evagrius Ponticus (not canonized as a saint)

Evagrius was born around 345 in Ibora, in the region of Pontus; he was ordained reader by St. Basil the Great and deacon by St. Gregory the Theologian, whom he served for a time as secretary in Constantinople. In 383 he withdrew to Egypt, where he lived as a monk in the deserts of Nitria and Kellia until his death in 399. He left an extensive ascetic and theological legacy, including the teaching on the eight principal sinful thoughts (logismoi), later transmitted in the West by Venerable John Cassian and transformed into the doctrine of the seven deadly sins, as well as writings on prayer and the spiritual life that greatly influenced Orthodox ascetic theology despite his subsequent condemnation by the Church.

IMPORTANT CAVEAT: Evagrius's teaching was posthumously condemned as Origenist heresy at the Fifth Ecumenical Council in Constantinople (553), the condemnation was reaffirmed at the Sixth Ecumenical Council, and Evagrius himself (together with Origen and Didymus the Blind) was explicitly anathematized by name at the Lateran Council of 649. A targeted check of azbyka.ru found no individual hagiography/commemoration page in its "/days/" section — Evagrius's presence on azbyka.ru is limited to the patristic literature library "/otechnik/," where he appears as an author of texts regardless of canonical status. There is no feast day in the Orthodox Church; pravenc.ru notes that Evagrius's name appears on February 11 only in the calendar of the Armenian Apostolic Church (a non-Chalcedonian body), not in the Orthodox calendar. Thus Evagrius Ponticus is a non-canonized, posthumously condemned historical theologian whose legacy nonetheless retains great significance for the Orthodox ascetic tradition.