Idowu was born on 28 September 1913, in
Ikorodu,
Lagos State, Nigeria. His early education was at the
Anglican and
Methodist schools in Ikorodu. There, he met the Rev. A. T. Ola Olude and was converted to Christianity. After finishing at Wesley College in
Ibadan, he became headmaster at the primary school in Remo,
Ogun State. He was ordained in 1942. From 1945 to 1948, he continued his studies at
Wesley House,
Cambridge. From 1957 to 1958, he was posted in Germany in an effort to resolve some of the problems that were facing African and Asian students there. In 1958 he joined the staff of the Department of Religious Studies at the
University of Ibadan and served as its head from 1963 to 1976. ==Church leader==