harrison was ordained in the church of england as a deacon in 1990 and as a priest in 1991. from 1990 to 1994, he served his curacy at st anne and all saints, south lambeth, in the diocese of southwark. he then moved to the diocese of bradford, where he was chaplain to the university of bradford, and to bradford and ilkley community college. during this time, he also served as the diocesan world development advisor.