The Saint Thomas Christians or Mar Thoma Christians are a group of Christians from the Malabar coast (now Kerala) in South India that follows the tradition of conversion to Christianity by St. Thomas the Apostle. The different groups and denominations within the St Thomas Christians together form the Nasrani people , who also follow Syriac Christianity traditions. The tradition goes back to the very beginning of first century Christian thought, and the seven churches that are believed to have been established by St. Thomas the Apostle in 52 AD. They are popularly known as Syrian Christians in view of the Syriac (classical form of Aramaic) liturgy used in church services since the early days of Christianity in India.
Mar Thoma Church, is Apostolic in origin, Universal in nature, Biblical in faith, Evangelical in principle, Ecumenical in outlook, Oriental in worship, Democratic in function, and Episcopal in character.
The Church presently has around one million members. The majority of the membership of the Church is in the southern Indian state of Kerala but it has spread with the 20th century Indian diaspora to North America, Europe, the Middle East, Malaysia, Singapore, South Africa, Australia and New Zealand, this in addition to a sizeable population in the rest of India.
The Metropolitan of the Mar Thoma Church is Rev. Dr. Theodosius Mar Thoma Metropolitan. He reside in Kerala, India. The Diocesan Center of the Diocese of North America and Europe is located in Merrick, New York and the Diocesan Bishop is Rt. Rev. Dr. Isaac Mar Philoxenos Episcopa.