He was the author of a Greek commentary on the Apocalypse, avowedly based upon that of Andrew, his predecessor in the archbishopric. In spite of its author's modest estimate, Arethas's work is by no means a slavish compilation; it contains additions from other sources, and especial care has been taken in verifying the references.
In the New Testament, 2 Peter, 2 and 3 John, Jude and the Apocalypse were originally left out, but Syriac versions were made at a later time.
But his two chief works, posthumously published, are his Cyprian (London, 1897), a work of great learning, which had occupied him at intervals since early manhood; and The Apocalypse, an Introductory Study (London, 1900), interesting and beautiful, but limited by the fact that the method of study is that of a Greek play, not of a Hebrew apocalypse.
Each fresh apocalypse would in the eyes of its writer be in some degree but a fresh edition of the traditions naturally attaching themselves to great names in Israel's past, and thus the books named respectively Enoch, Noah, Ezra would to some slight extent be not pseudonymous.