John joined the staff of the World Evangelical Fellowship on 1st September 1969 as assistant to Bruce Nicholls, the Executive Director of the WEF Theological Commission, initially full-time in India and Singapore and then on a part-time basis until 1983.

In 1980 he joined the WEF International Council as council member and treasurer, a position he still holds. In 1992 he became the chairman of the WEF Religious Liberty Commission, a position he still holds. He is a board member of Advocates International, an affiliate of the WEA.