From 1938 to 1946 he served as a Methodist minister in New Eltham and Chislehurst (southeast London). He came to public notice in 1945 when he challenged the charge that Martin Luther was the spiritual ancestor of Hitler. The charge was made by Peter F. Wiener in a widely distributed pamphlet, Martin Luther: Hitler's Spiritual Ancestor.[1]
In 1946, Rupp served as the assistant to the Principal of Wesley House. In 1947, he was appointed assistant professor at Richmond College.[4]
Holy Book and holy tradition: International colloquium held in the Faculty of Theology, University of Manchester. ed. F.F.Bruce & E. Gordon Rupp. Manchester, England: Manchester University Press, 1968.
Rupp, E. Gordon. "I seek my brethren:" Bishop Bell and the German Churches. London: Epworth, 1975.
Rupp, E. Gordon. Is this a Christian Country?, 1941.
Rupp, E. Gordon. Luther's progress to the Diet of Worms, 1521.NL: NP, 1951.
Rupp, E. Gordon. The King of Glory: Studies in St. Paul's Epistle to the Colossians. London: Epworth Press, 1940.
Rupp, E. Gordon. Martin Luther, Hitler's Cause or Cure? London and Redhill, Lutterworth press, 1945.
Rupp, E. Gordon. Religion in England 1688–1791. London : S.C.M. Press, 1975.
Rupp, E. Gordon. The Righteousness of God: Luther studies. London: Hodder and Stoughton, 1953.
Rupp, E. Gordon. Study in the making of the English Protestant Tradition, Mainly into the Reign of Henry VIII. Cambridge, England: Cambridge University Press, 1947.
Rupp, E. Gordon. Thomas More: the King's good servant, New York : Collins, 1978.
Rupp, E. Gordon. Principalities and Powers: Studies in the Christian Conflict in History, London: Epworth, 1952.
Rupp, E. Gordon. Patterns of Reformation, London: Epworth, 1969.