A graduate of the Hellenic College, Brookline, Massachusetts, and of the Yale Divinity School, he received his Doctor of Philosophy from the University of Athens.
From 1956 to 1965 he was Professor of Dogmatic at the Holy Cross Theological School in Brookline, Massachusetts. In 1968 he was appointed as tenured Professor of Dogmatic at the University of Thessaloniki, Greece, a position he held until his retirement in 1982. His latest position was Professor of at Balamand Theological School, in Lebanon.
Romanides died in Athens, Greece on 1 November 2001.
His theological works emphasize the empirical basis of theology called theoria or vision of God, (as opposed to intellectual-contemplative) as the essence of Orthodox He identified Hesychasm as the core of Christian practice and studied extensively the works of 14th century hesychast and theologian Saint Gregory Palamas. His research on Dogmatic led him to the conclusion of a close link between doctrinal differences and historical developments.
Thus, in his later years, he concentrated on historical research, mostly of the Middle Ages but also of the 18th and 19th centuries.