Sargent was born near London,[1] and educated at Watford Grammar School for Boys, King's College, Cambridge[3] and the London College of Divinity; and ordained in 1932.

[4] Subsequently, he embarked on a long spell as a missionary[5] in Sichuan Province[6] at West China Union University,[7] where he worked as a lecturer.

During his stay in Sichuan, he became chaplain to Bishop C. T. Song and assistant secretary for the Church Missionary Society.

[1] In 1942 he married Imogene Ward, the daughter of American Methodist missionaries.

[1] From 1961 until 1962 he was principal of the Church Missionary Society[8] when he was elevated to the episcopate,[9] a post he held until his retirement to York.