Early life and pastoral career
Chamberlain was born in Christchurch, New Zealand, the eldest son of Ivan and Greta Chamberlain. His father served as a warrant officer in the Royal New Zealand Air Force during World War II, while his mother was involved with the administration of the Seventh-day Adventist Church in southern New Zealand.
Educated at Lincoln High School and Christchurch Boys' High School, Chamberlain commenced studies at the University of Canterbury but after converting to the Seventh-day Adventist Church in 1965, he left and migrated to Australia. He subsequently studied at Avondale College in Cooranbong and graduated with a Bachelor of Arts (Theology) degree in 1969. He married Lindy Murchison the same year, after meeting her in 1968.
After graduating, Chamberlain worked as a Seventh-day Adventist minister in Tasmania, where Lindy Chamberlain gave birth to two children—Aidan (born 1973) and Regan (born 1976). In 1977 the family moved to Queensland, where Chamberlain produced and presented a radio program called The Good Life, a commentary on lifestyle and culture throughout the northern parts of the state. The Chamberlains' third child, daughter Azaria, was born in Mount Isa on 11 June 1980.