Kalloor Chacko is the fourth of seven sons born to Kalloor Koshy. Koshy is the patriarch of the Kalloor family in Thrikkannamangal, Kottarakara. His elder brother is the patriarch of the Thondel family. After Koshy's mother died, his father married again and had a third son, who is the patriarch of the Kalluttankuzhy family.
Chacko is uniquely remembered for his role as the catalyst in the birthing of the modern Pentecostal movement in India. Coming into contact with the American missionary, Robert F. Cook, in the 1920s, Chacko invited Cook to move to Thrikkannamangal from North India. Cook, after surveying the area, set up headquarters for his mission work in a rented house adjacent to Chacko's house. Chacko and Cook worked hand in hand to set up the first Pentecostal church in India. Chacko set aside part of his land for this, though he never signed it over to Cook's church. As the work progressed, Cook's work expanded to other areas of Kerala, establishing churches in places like Thuvayoor. Cook joined the Church of God (Cleveland, Tennessee) and proceeded to bring all of his mission works into the Church of God. Several of his primary co-workers parted company and began their own organizations, such as the India Pentecostal Church of God and the Ceylon Pentecostal Mission. These two groups are now the largest Pentecostal churches in India, boasting over a million members each. Though Chacko continued to support Cook's work for some time, they also parted company over doctrinal and organizational differences and Cook relocated the headquarters of the Church of God (Full Gospel) in India to Mulakuzha. Chacko retained ownership of the church and property, which remains the oldest registered Pentecostal church in India. This church is now owned by his grandson, John Mathew.
WIthout the involvement of Chacko, the religious landscape of India might have looked very different today. The work brought to life by his partnership with Cook has spawned countless spin-offs that now cover the whole country with the Pentecostal message. The is not a single main city or town in India now without the presence of some Pentecostal church. The movement boasts 20-30 million members, depending on who does the reporting. Except for the Assemblies of God, almost all other Pentecostal works in India trace their roots back to the partnership of Cook and Chacko in the small town of Thrikkannamangal, Kerala.
Chacko's information is referenced primarily in Cook's autobiography, Half a Century of Divine Leading and 37 Years of Apostolic Achievements in South India (Cleveland, TN: Church of God Foreign Missions Dept.), 1955. Much of the information have also been gathered through interviews conducted in the town of Thrikkannamangal and among leaders of Church of God (Full Gospel) in India.