William has been in ordained Anglican ministry since 1998, serving in a number of parishes in the Church of England and the Church of Ireland. Prior to ordination he was a lawyer, having been called to the Bar of England and Wales in 1993. He holds a doctorate in biblical hermeneutics from Liverpool University (2007) and has taught part-time at the Church of Ireland Theological Institute since 2013. He is an adjunct associate professor in the School of Religion, Theology, and Peace Studies at Trinity College Dublin. He has been involved in the Scripture and Hermeneutics Seminar since 1999 and was, until 2024, a trustee of the Kirby Laing Centre.