Like his famous father, Moffat was a Congregationalist minister affiliated with the London Missionary Society but he became involved in British colonial expansion particularly in Matabeleland, later part of Southern Rhodesia, now Zimbabwe. His missionary work included helping to start the first mission in Matabeleland in 1859 at Inyati. In 1865 he took over the running of his father's mission in Kuruman. In 1879 he resigned from the missionary society and joined the British Bechuanaland colonial service.
