As an exegete Theodoret belongs to the Antiochene school, of which Diodorus of Tarsus and Theodore of Mopsuestia were the heads.
As an exegete and biblical critic no less than as a grammarian he has left his abiding mark.
Lucian the great exegete of Antioch and his school derived their inspiration from Paul, and he was through Lucian a forefather of Arianism.
As an exegete he exercised a powerful, and on the whole a beneficial, influence on theological investigation.
A moderately liberal theologian, he became best known as a New Testament critic and exegete, being the author of the Commentary on the Synoptics (1889; 3rd ed., 1901), the Johannine books (1890; 2nd ed., 1893), and the Acts of the Apostles (1901), in the series Handkommentar zum Neuen Testament.