The papers comprise correspondence, sermons, addresses, lectures, writings by Engel, minutes, reports, leaflets, articles, conference papers, cuttings, notes, publications and other papers relating primarily to Engel's involvement in the New Zealand Student Christian Movement, Australian Frontier, Overseas Service Bureau, World Council of Churches, Australian Council of Churches, Action for World Development and the Christian Conference of Asia. They also include a large sequence of files relating to Aboriginal land rights and issues, and a copy of Engel's unpublished autobiography entitled 'Rarely a dull moment'.