He was born in 1914 in the Panampunna family at Kottayam and was a deep scholar who continued his reading and studies to the end of his days. He was known for his deep devotion and great ability to build up the Church. He had his earlier education at the C.M.S College Kottayam and later as at Trivandrum where he took Post Graduation in History from the Arts College.
He had his Theological training at the Bishop’s College Calcutta and at Oxford University, England. He taught in the Mar Thoma Theological Seminary and the M.T High School Kottayam. He was ordained Deacon of the Church in 1944 and Kasseessa in 1946 while he continued his teaching at the Mar Thoma Theological Seminary.
On his consecration as Bishop in 1953 with the other two Bishops, he was first in charge of the Diocese in Kerala, South of Adoor, called the Southern Diocese at that time. After six years in this capacity, he functioned as Missionary Bishop from 1959 to 1963. Since then he has been in charge of the Northern Diocese with head quarters first at Kottayam, and later at Manganam.
He attended the first Assembly of the World Council of Churches at Amsterdam in 1948, and also the Assembly at New Delhi in 1961. He was a member of the Faith and Order Commission of the World Council of Churches since 1961. Thus he made significant contributions to the cause of ecumenism. He has attended many other international conferences in the Churches and was a delegate to the Melbourne Conference where he had made a distinct contribution as a leader of Bible Study. He also attended the sessions of the second Vatican Council on special invitation.
He was designated as Suffragan Metroploitan in May 1978 together with Philipose Mar Chrysostom.
He has been President of various organizations of the Church, such as the Evangelistic Assocaiation, Sunday School Samajam, Sevika Sangham and Yuvajana Sakhyam on different occasions. He guided the evangelistic activities of the whole church for many years.
As a builder, he opened up many centers for the development of the church, raising funds by personal appeals. Thus were established the Diocesan Headquarters at Adoor, Maganam and Kunnamkulam. The Church Center at Chungathara, the Convention Speakers Sites in the Retreat Centre at Maramon, and the St. Augustine Study Centre, Manganam, Kottayam with the view that the clergy and Laity should take time off to stay at the center and read the latest books on theology and related subjects. By his personal efforts, he built a library of over 6000 valuable books.
The Mar Thoma College for Women at Perumbavoor was established under his inspiring leadership and patronage.
He gave leadership to the Parishes in the Ranny area to establish a center for the church. He was Cahirman of different colleges of the Church and of the Vaidika Seminary for many years and gave valuable contributions to their development. The last months of his life were spent in organizing and developing the Parishes in North America. His sudden demise on November 27, 1984 was a severe shock to the whole Church and to the ecumenical world. His loss was irreparable.
He was awarded a Doctorate by the Serampore University considering his meritorious services to the Church in India, and towards ecumenical cause.
At the time of his consecration as Bishop a controversy was started by Mr. K N Daniel who questioned his loyalty to reformation principles. After closely observing his life and work for some years, Mr. Daniel himself admitted that his fears were unjustified and he had full confidence in Mar Athanasius’s personal commitment to Jesus Christ, his evangelical zeal and loyalty to the Church.