Rev Abraham Caldwell was born in 1916 to Christian parents Koilpillai and Grace. His father, whose last job was station master at the Segamat railway station, was grateful to Bishop Robert Caldwell for his education in India and hence he gave his son the name "Caldwell".
Abraham Caldwell had two older brothers, Robert and Edward. When his father died in his thirties, his mother took the children to India and settled in Nazareth in Tirunelveli, South India.
At the age of 16, Abraham Caldwell returned to Malaya and stayed for a time with his uncle in Kuantan before moving to stay with his brother, Robert, in Kuala Lumpur. While working as a postal clerk in the General Post Office in Kuala Lumpur, he became acquainted with Florence Rajamoney. They were married and had eight children: Jebamani (Mani Thomas), Sama, Victoria, Rajan, Kiruba (Grace), Inban, Amirthamoney and Barnabas.
During World War II (1942-1945), the family lived in Batu Caves in Selangor where he was the postmaster. On one occasion during the war, he had to hide in a cemetery for five days.
Following the war, the family moved to India and then to Sri Lanka before coming to Singapore in 1955. His preparation for ministry included "street preaching" in Sri Lanka in the immediate post-war years. When he came to Singapore, he worshipped at the Church of the Ascension where he subsequently became an honorary lay leader. He served as a laboratory technician at the Department of Medicine, University of Singapore, in the 1950s and took up part-time theological studies at Trinity Theological College, Singapore.
He was a full-time student during his final years of theological studies at St. Peter's Hall, Trinity College. His family was supported financially by his father-in-law who was an honorary lay leader in Christ Church Singapore.
He was ordained deacon and priest by Bishop Kenneth Sansbury in 1960 and served at our Saviour's Church, Singapore from 1961-1965. He also served in Malaysia at St. Barnabas Klang (1966-1968), St. James Sentul (1968-1971), and St. Christopher's Johor Bahru (1971-1973).
He rejoined the Diocese of Singapore as vicar of Christ Church (1973-1980). He also strengthened the Church of the Epiphany at Jalan Kayu, Singapore during his ministry. He retired in 1980 and passed away in 1981 in Singapore.