After teaching for some more years at Perumbavoor, he went for higher theological training at Princeton and took Masters from there and Doctorate from Boston University. He has worked as Vicar of Parishes in Mumbai and Kozhenchery and was consecrated as Bishop on May 1, 1980. He was given charge of the Adoor- Mavelikkara Diocese till 1984. As the Bishop in charge of the Diocese, he organized a project at Pathanapuram for helping disabled persons, the Asha Bhavan. He also organized a project to help the poor people along the sea coast at Thrikunnapuzha area. He helped in setting up a working women's hostel at Haripad and Pathanamthitta. Mar Theophilus is in charge of the Chengannur - Mavelikkara Diocese. He was a member of the Central Committee and the Executive Committee of the World Council of Churches.
