Keyword “may.”
Also I’m not talking about Hagiography but about historical documents by the early church; dismissing all Patristic writing as Hagiographic is simply wrong, and it also results in discarding all of the doctrinally orthodox Christian writers about Christianity, so one is left with texts by heretics like the Valentinians, Ophites and Manicheans, and texts by non-Christians.
Interestingly a small minority of Patristic writing can be regarded as Hagiographic, primarily hymns about the martyrs and the Blessed Virgin Mary, and the vast majority of these postdate the fifth century.
The only major Patristic writings we could regard as hagiographic outside the realm of the martyrologies, synaxaria and so on, which I was not referring to, by the way, are works such as The Life of Anthony by St. Athanasius. However, calling this hagiographic is misleading, since while this work contributed to the veneration of St. Anthony and St. Paul the Hermit and the Desert Fathers as saints, it was not composed after they were already venerated; furthermore, St. Athanasius can be regarded as a reliable historical source because he was protodeacon and later patriarch of the Church of Alexandria for most of St. Anthony’s life, with personal knowledge of him, and thus firsthand information, and also he happens to have been the primary defender of the doctrine of the Incarnation against Arius at Nicaea, instrumental in the development of the first recension of the Nicene Creed (additionally, the Athanasian Creed, while not written by St. Athanasius, is a later synthesis of two of his writings on the Incarnation and the Trinity, thus two of the three historic creeds, including the initial recension of the most important one, resulted from his work (and St. Gregory the Theologian initially convened the Council of Constantinople, which revised the Nicene Creed to the current version, and was, like the other Cappadocians, a correspondant with and ally of St. Athanasius).
Finally, St. Athanasius in 367 AD promulgated his 39th Paschal Encyclical, containing the date of Easter calculated according to the formula adopted across the entire church at Nicaea, also included a New Testament canon for the Church of Alexandria, which was adopted by all other churches, even those which at the time were leaning towards a narrower or broader canon (the Syriac Peshitta had a 22 book New Testament lacking Revelation, Jude, 2 John, 3 John and 2 Peter, but the Syriac Orthodox church added the missing books in the sixth century and they were later recognized as canonical by the Assyrian Church of the East, and the Syriac Orthodox version of the Peshitta is the one used by the Maronite Catholics who separated from the Syriac Orthodox in a schism centuries before entering into communion with Rome, and whose liturgy and that of the Syriac Orthodox and a few other related churches is called “the West Syriac liturgy”; before ill-advised reforms after Vatican II, much of it was identical to the Syriac Orthodox liturgy. Conversely, two of the three ancient Alexandrian text type Bibles, the Codex Sinaitcus and Codex Alexandrinus) contain additional New Testament books that were either Patristic rather than Apostolic (such as 1 Clement and the Shepherd of Hermas) or psuedepigraphical forgeries (2 Clement, 1 Barnabas). Thus we have St. Athanasius to thank for the 27 book standard we enjoy, and this gives his Life of Anthony a level of credibility that exceeds that most hagiographic text.
Also it may surprise you to know that the Orthodox and Roman Catholics both are aware of errors and duplications in hagiography, for example, the Copts regard their Synaxarion as less reliable than the Ethiopian, because, for example, it confuses the church historian Eusebius of Caesarea, venerated by their sister church the Syriac Orthodox as a saint, with the sinister Arian bishop Eusebius of Nicomedia, who did not attend Nicaea but instead ingratiated himself in court life, baptizing St. Constantine on his deathbed and persuading his son Constantius to convert to Arianism and begin an ongoing persecution of Christians that would last until 386 AD in the Roman government, and later, after the Christian emperor Theodosius (the first Christian since St. Constantine, or if you prefer, and I don’t, the first Christian not tainted by the heresy of Arianism, which I regard as so heretical as to make someone a non-Christian, and that is also the position of the CF statement of faith if memory serves, that non-Trinitarians are regarded as non-Christian, since the doctrine of the Incarnation really is essential to Christianity) was persuaded by a vigil orchestrated by St. Ambrose, the bishop of Milan, to not turn over a parish church in Milan to the Arians in the interests of avoiding ciivl unrest (which in the event, did not happen, so St. Theodosius nearly gave away a Christian church to the 4th century equivalent of the Jehovah’s Witnesses for no reason). After that point however, Gothic tribes who had been converted to Arianism by Arian missionaries were involved in the repeated sacking of Rome, the later conquest of Italy by the Ostrogoths, and then the Visigoths of North Africa converted to Islam and were involved in the genocide against all African Christians outside of Egypt and Ethiopia.
