Agapius was a Christian

Christianity

Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

 philosopher associated with Manichaeism

Manichaeism

Manichaeism in Modern Persian Āyin e Māni; ) was one of the major Iranian Gnostic religions, originating in Sassanid Persia.Although most of the original writings of the founding prophet Mani have been lost, numerous translations and fragmentary texts have survived...

. He is supposed to have lived in the fourth or fifth century.

Identity

He is chiefly known for being mentioned in the Bibliotheca

Bibliotheca (Photius)

The Bibliotheca or Myriobiblon was a 9th century work of Byzantine Patriarch Photius, dedicated to his brother and composed of 279 reviews of books which he had read. It was not meant to be used as a reference work, but was widely used as such in the 9th century, and is generally seen as the first...

, a work by Photius, the ninth-century Patriarch of Constantinople. He is listed by Photius, as well as Peter of Sicily, as being among the twelve disciples of Mani

Mani (prophet)

Mani , of Iranian origin was the prophet and the founder of Manichaeism, a gnostic religion of Late Antiquity which was once widespread but is now extinct...

. However, in earlier sixth-century works, such as the abjuration formula of Zacharias Mitylene and the handbook on abjuration of heresies by Presbyter Timothy of Constantinople, he is not listed as a Manichean but merely as the author of a work entitled the Heptalogue (Heptalogus).

Photius also describes Agapius as challenging the teachings of Eunomius, who, according to Samuel N.C. Lieu, may be identified as Eunomius of Cyzicus

Eunomius of Cyzicus

Eunomius , one of the leaders of the extreme or "anomoean" Arians, who are sometimes accordingly called Eunomians, was born at Dacora in Cappadocia early in the 4th century....

, the Arian

Arianism

Arianism is the theological teaching attributed to Arius , a Christian presbyter from Alexandria, Egypt, concerning the relationship of the entities of the Trinity and the precise nature of the Son of God as being a subordinate entity to God the Father...

 bishop of Cyzicus

Cyzicus

Cyzicus was an ancient town of Mysia in Anatolia in the current Balıkesir Province of Turkey. It was located on the shoreward side of the present Kapıdağ Peninsula , a tombolo which is said to have originally been an island in the Sea of Marmara only to be connected to the mainland in historic...

 in Mysia

Mysia

Mysia was a region in the northwest of ancient Asia Minor or Anatolia . It was located on the south coast of the Sea of Marmara. It was bounded by Bithynia on the east, Phrygia on the southeast, Lydia on the south, Aeolis on the southwest, Troad on the west and by the Propontis on the north...

. Agapius, however, could not have both been a disciple of Mani, who died in 276, and have lived long enough to write against Eunomius of Cyzicus

Eunomius of Cyzicus

Eunomius , one of the leaders of the extreme or "anomoean" Arians, who are sometimes accordingly called Eunomians, was born at Dacora in Cappadocia early in the 4th century....

, who began as bishop in 360.

Writings

Photius described reading an unidentified work, possibly the Heptalogue, by Agapius that contained "23 fables and 102 other sections", where Agapius feigns his own Christianity but reveals himself as an "enemy" of Christ. Agapius dedicated his work of twenty-three chapters to his female fellow philosopher Urania.

Photius summarizes Agapius' apparently Manichaean teachings as follows:
Agapius, however, appears to have also endorsed ideas unrelated to Manichaeism, such as Orthodox Christian concepts like "the Trinity, the Incarnation, the Baptism, Crucifixion and Resurrection of Christ, the Resurrection of the Dead and the Last Judgment." Photius claims Agapius was able to do so by "altering and translating almost all the terms of piety and of the Christian religion into other meanings..."

Photius mentions that Agapius made use of apocryphal Christian literature

New Testament apocrypha

The New Testament apocrypha are a number of writings by early Christians that claim to be accounts of Jesus and his teachings, the nature of God, or the teachings of his apostles and of their lives. These writings often have links with books regarded as "canonical"...

, especially the Acts of Andrew

Acts of Andrew

The Acts of Andrew , is the earliest testimony of the acts and miracles of the Apostle Andrew. The surviving version is alluded to in a 3rd century work, the Coptic Manichaean Psalter, providing a terminus ante quem, according to its editors, M.R. James and Jean-Marc Prieur in The Anchor Bible...

, and pagan philosophy in his arguments:
Agapius is also described as an author of hymns.