A theologian is generally understood to be a person who teaches or is educated in theology. Its root form, theology, is derived from the Greek θεολογία (theologia), from θεός (theos, god) and λόγος (logos), with the suffix ια (ia, "state of," "property of," "place of"). A literal translation of the Greek word would be "to talk about God." However, Orthodoxy has privileged the meaning of the term given by Evagrius Ponticus when he wrote that "If you are a theologian, you will pray truly. And if you pray truly, you are a theologian." (Treatise On Prayer, 61).
Theologians use various forms of analysis and argument to help understand, explain, test, critique, defend, or promote religious topics. Theology had its origin in classical Greek thought, but was given new senses within the Christian context as the Fathers of the Church.
Among the many theologians of the Orthodox Church are three saints given the appellation Theologian: John the Theologian, Gregory the Theologian, and Symeon the New Theologian.
Other theologians of the early church include: Clement of Alexandria, Basil the Great, Theodore the Studite, Leo the Great, and John Chrysostom.
Among modern theologian are: Vladimir Lossky, Stylianos (Harkianakis), Jaroslav Pelikan, Justin Popovich, Alexander Schmemann, and Pavel Florensky.