Having taken [[monasticisn|monastic]] vows and receiving the name Theodoros, he was [[ordination|ordained]] a [[deacon]]. From 1975 to 1985, Dn. Theodoros served as Archdeacon and Chancellor of the Holy Metropolis of Lambis and Sfakion in Crete. Here he developed significant preaching and philanthropic activities, such as at hostels for needy youth. From 1985 to 1990, during the tenure of Patriarchs Nicholas VI and Parthenios as Patriarchs of Alexandria, he served as Patriarchal Exarch in Russia, based in Odessa, Ukraine. There he established the Institution of Hellenic Culture and the Philiki Eterea Museum where 600 children were taught a thorough knowledge of Greek.
In 1997, he was appointed Patriarchal Vicar by Patriarch Petros VII, to assist assist the new patriarch at the outset of his Patriarchate. Ten months later Bp. Theodoros was elected Metropolitan of Cameroon. As the leader of this [[missionary]] [[diocese]], Metr. Theodoros greatly expanded the missionary activity in the diocese. He encouraged the building of [[church]]es, schools, and hospitals, as well as helping many Africans and Hellenes.