Gennadius of Marseilles ("de Vir. Ill." 12) represents Theodore as a presbyter of the church of Antioch; and from a letter of John of Antioch (Facund. ii.2) we gather that forty-five years elapsed between his ordination and his death. That would mean he was ordained priest at Antioch in 383, in his thirty-third year, the ordaining bishop being doubtless Flavian, Diodore's old friend and fellow-laborer, whose "loving disciple" Theodore now became (John of Antioch, ap. Facund. l.c.). The epithet seems to imply that Theodore was an adherent of the Meletian party, but there is no evidence that he was involved in the feuds which preoccupied the Catholics of Antioch during Flavian's office. Theodore's great treatise on the Incarnation belongs to this period according to Gennadius, and possibly also more than one of his commentaries on the Old Testament. As a preacher he seems to have now attained some eminence in the field of polemics (Facund. viii.4). Theodore is said by Hesychius to have left Antioch while yet a priest and remained in Tarsus until 392, when he was consecrated to the see of Mopsuestia on the death of Olympius, probably through the influence of Diodore. Theodoret states he spent his remaining thirty-six years of life in this town.