Sparks was ordained in the Church of England as a deacon on 24 September 1933 by Thomas Strong, the Bishop of Oxford, and as a priest in 1934. From 1933 to 1936, he combined his curacy at All Saints Church, Oxford, and a position as an honorary chaplain of Ripon Hall. Additionally, he assisted H. J. White with the production of a new version of the Vulgate New Testament between 1933 and White's death in July 1934. He resigned from Ripon Hall in 1936 because of the increasing influence of the Modern Churchmen's Union on the theological college.
