Constantius' successor
Julian (later called "The Apostate") was the only emperor after the conversion of Constantine to reject Christianity, attempting to fragment the Church and erode its influence by encouraging a revival of religious diversity, calling himself a "
Hellene" and supporting forms of
Hellenistic religion. He championed the
traditional religious cultus of Rome as well as Judaism, and furthermore declared toleration for all the various unorthodox Christian sects and schismatic movements.
The Edict of Thessalonica was issued under the influence of
Ascholius, and thus of
Pope Damasus I, who had appointed him. It re-affirmed a single expression of the Apostolic Faith as legitimate in the Roman Empire, "
catholic" (that is, universal)
[5][6] and "
orthodox" (that is, correct in teaching).
[7]
After the edict, Theodosius spent a great deal of energy trying to suppress all non-Nicene forms of Christianity, especially Arianism, and in establishing Nicene orthodoxy throughout his realm.
[8]
The edict was followed in 381 by the
First Council of Constantinople, which affirmed the Nicene Symbolum and gave final form to the
Nicene-Constantinopolitan Creed.
[9]