Most Rev. Dr. Joseph Mar Thoma was the Mar Thoma Metropolitan, the title given to the supreme head of the Church, of The Malankara Mar Thoma Syrian Church, often condensed as Mar Thoma Church, from 2 October 2007 to 18 October 2020. He was preceded by Most Rev. Philipose Chrysostom Mar Thoma and Succeeded by Most Rev. Theodosius Mar Thoma.

The 89 year old Metropolitan Joseph Mar Thoma entered into his eternal life in the early morning on 18 October 2020 after a prolonged illness. He diligently shepherded the Church for thirteen years till his last day of departure from this world. Joseph Mar Thoma was a prominent church leader in the country who was champion of the movements against social evils, in the field of charity and in ecumenical efforts for unity of churches.

P.T. Joseph also known as Baby was born on 27 June 1931, as the son of P. T. Lukose of Maramon Palakunnathu Kadon House and Mariamma of Maramon Puthoor House. Grandfather of Joseph, Kadon Thomas was the brother of Titus II Marthoma Metropolitan. Maramon Palakkunnathu family has the rare distinguished heritage of contribution of five Metropolitans to the Church. The first Metropolitan from the family was Mathews Mar Athanasius, son of the elder brother of the father of reformation Abraham Malpan. Mathews Mar Athanasius was the first Metropolitan of the church. Thomas Mar Athanasius, who succeeded him, was the second son of Abraham Malpan. Titus I and Titus II Metropolitans were also from same family.

After his school education at Maramon and Kozhencherry, he joined Union Christian College, Aluva where he was a member of the college basketball team. Further as per call for ministerial service he joined the United Theological College, Bangalore in 1954, and obtained a degree of Bachelor of Divinity. He was ordained as a deacon on 29 June 1957 and a priest on 18 October 1957. Subsequently he proceeded for higher education in theology at the Protestant Episcopal Seminary in Virginia, United States. Further he went to Canterbury and Oxford in England and obtained Master of Divinity (M.Div.) and Master of Sacred Theology (STM) degrees. He was later awarded an honorary Doctor of Divinity degree by the Virginia Seminary where he did his theological study.

In 1974 the Church representative assembly Mandalm had elected Fr. P.T Joseph to be raised to Episcopal level. He was ordained as Ramban on 11 January 1975. On 8 February 1975, Juhanon Mar Thoma, Metropolitan, ordained Rev. P.T. Joseph as a Bishop and was given the Episcopal title of Joseph Mar Irenaeus along with Rev. V.T. Koshy with title as Easow Mar Timotheos.

On 15 March 1999, he was designated as Suffragan Metropolitan, when Philipose Mar Chrysostom, the then Suffragan Metropolitan, was consecrated as the officiating Mar Thoma Metropolitan. When the Philipose Mar Chrysostom Mar Thoma Metropolitan expressed his desire to get relinquished from responsibilities of the church as Metropolitan due to old age and deteriorating health Joseph Mar Irenaeus was elected as the successor. Mar Chrysostom continued as 'Valiya Metropolitan' or Metropolitan Emeritus. Joseph Mar Irenaeus was consecrated as Mar Thoma Metropolitan on 2 October 2007.

Joseph Mar Thoma had devoted his life for the marginalized, poor, sick, disabled, transgender, homeless and downtrodden in the society. Metropolitan brought about revolutionary efforts to bring transgender people to the forefront of social order. He was instrumental for establishing the Prathyasa Bhavan in Pathanapuram and Jyothis in Mavelikkara for the disabled. Prathyasa Bhavan Half-Way-Home is an ambitious project of the Ranni-Nilackal Diocese of the Malankara Mar Thoma Syrian Church for the rehabilitation of recovered mental patients. Jyothis is a training centre for mentally challenged children, which looked beyond the limitations of caste and community commenced under Adoor - Mavelikkara Diocese of Marthoma Church. He also initiated the Navajeevan movement for abandoned children of prostitutes in Mumbai's Red Street.

The ambitious project of 100 houses for flood victims was a milestone task of this human lover. By making radical changes in the schedule, Joseph Mar Thoma had lifted the ban on women attending night meetings at Maramon Convention, one of the largest Christian convention in Asia organized by Mar Thoma Evangelistic Association, the missionary wing of the Mar Thoma Church.

Most Rev. Joseph Marthoma Metropolitan was associated with humble efforts of Light of life by contributing many articles and support in the publication. LOL bestow respectful homage and pay tribute to this great human loving and kind Metropolitan.