Thomas was born on 4 January 1884 at Chingavanam in Kottayam as the second son of Thomman Kuruvila and Pallam Ottathaickal Naithiyamma of the Thervalady family.  He received the sacred order of Diaconate after his studies at the CMS School, Pallam and at the CMS College, Kottayam.  He was ordained priest at the age of 28, by Metropolitan Idavazhickal Mar Severios. As a member of the Knanaya Jocobite Church, he was recommended to succeed Metropolitan Mar Severios when the latter passed away. He was ordained Bishop after the name Deoscoros by Eliaz III, Patriarch of Antioch, on 11 November 1926 in Jerusalem.  He governed the Church from 1927 to 1939 staying at the Mar Ephraem Seminary, Chingavanam.  As a result of his Theological studies, he developed a deep spiritual affection towards the Catholic Church (the true Church).

           Due to his irresistible desire to commune with the Catholic Church, he went to Archbishop Mar Ivanios and on 12 November 1939 made his profession of the Catholic faith before him. In order to lead a life of prayer, he relinquished his offices and went to Cherupushpagiri, Tiruvalla and stayed with Mar Theophilos and Mar Severios.  He spent his last days in the church at Tirumoolapuram.  He passed away on 22 February 1943 and is buried at the St. Mary’s Church, Tirumoolapuram.