He was ordained a priest on 12 August 1945. He holds a BA in theology and in philosophy and Oriental history and a doctorate in theology. He held various teaching positions and in 1960 was appointed professor at the University of Louvain. The Bishops of Belgium designated him professor of the history of religions in the faculty of theology and in the Oriental institute, founding the Centre forthe history of religions.
In 1969 the University was transferred and rebuilt in Louvain-la-Neuve and he was given the task of reorganizing the library. From 1975-1980 he served as president of the Louvain’s Oriental Instituteand from 1979-1985 as consultor of the Secretariat for Non-Christians. In 1986 he received the Dumas Millier prize for his publications and in 1987, the Furtado prize for his scientific work as a whole. He retired in 1991 and is considered one of the great religious anthropologists, having written extensively in the field.
On 6 January 2012 he was appointed titular Archbishop of Bellicastrum. He received episcopal ordination on 11 February 2012.
Created and proclaimed Cardinal by Benedict XVI in the consistory of 18 February 2012, of the Deaconry of S. Antonio di Padova a Circonvallazione Appia (St. Anthony of Padua).
Cardinal Julien Ries died on 23 February 2013.