Upon graduating from the University of Toronto, Oliphant returned to Sault Ste. Marie and worked at Algoma Steel as an accountant in computer systems development. He remained in Sault Ste. Marie for two years before entering the Vancouver School of Theology at the University of British Columbia. He was sponsored as a candidate for ministry by his home church, Central United Church in Sault Ste. Marie. After completing his Masters studies at UBC, Oliphant was ordained as a United Church minister in 1984. He has been stationed in diverse communities such as Montreal, Toronto, Quyon, Quebec, Newfoundland and Whitehorse.