I was wondering what is the scholarly consensus and textual reliability regarding St. Cyprian’s Unity of the Church as well as the majority of the early church fathers, thanks.
The reliability of the writings of the “Church Fathers” varies widely. For example, the First Letter of Clement of Rome is considered by most to be a genuine letter of Clement from the late 90s AD, while the second and third letters of Clement are seriously doubted. This is because of the lack of early quotes from these later letters, as well as the style and the content. I have studied the early church literature extensively, but I am not a qualified expert to comment on all these writings. What I can say is that Unity of the Church by Cyprian is one of those documents about which scholars are quite confident. This letter was used by contemporaries extensively. They quote from the letter and give credit to Cyprian. Also, the context of the letter tells us it is by Cyprian, because we know quite a bit about his life. You should probably suspend all or nearly all doubt about the reliability of this letter. Most of what we have from the most important writers, such as Jerome, Augustine, Origen and Irenaeus are probably genuine. Those of others can be taken on a one-at-a-time basis. Because these are not inspired writings, the absolute assurance of the author of particular church father writings is not as essential to the Christian faith as the scriptures.
About Cyprian, he is a true hero of early Christianity. He was born into wealth and position. He rose very high in the Roman government of Carthage. When he was converted his transformation was complete. He was made bishop of Carthage within a very short time (probably too short for biblical standards, but…). This was based on his wisdom, his training, but also on his deep spirituality. Cyprian was orthodox in his teaching. He opposed the Novatian heresy of the mid-third century, as he should have. However, there is a significant downside to Cyprian. In his opposition to the Novatians (who taught that those who have sinned by denying Christ cannot be returned to Christian fellowship), he resorted to ideas which led eventually to Roman Catholicism and a falling away from the biblical form of worship. For example, he argued that salvation is found, not in a personal faith decision, based on repentance and baptism, but on taking part in the “sacraments” of the Church. He taught not only that there is only one Church (true), but that anyone who is not a member of the church headed by the hierarchy in Rome (or perhaps in Carthage) is not saved. Salvation is found, not in faith and repentance, but through the sacraments, penance, and participating in worship under the leadership of a bishop authorized by a single, hierarchical church structure. We can see here the beginnings of what became Orthodox and Roman Catholic Christianity. He was a very strong supporter of the authority of metropolitan bishops. He also supported the growing dependence, not on personal repentance to maintain righteousness, but on acts of “penance” determined by the local bishop.
I am not sure the context of your question, but many Roman Catholics will try to “prove” using quotes from Cyprian that they are the only church and that salvation is only found within their peculiar system. I already said that the letter you refer to is genuine and “authoritative” in that it is what he wrote. However, it is not inspired and attempts by Catholics to prove they are right and you are wrong using this book are based on a false idea of authority. I would add that if we were to somehow resurrect Cyprian today and present-day Catholics were to ask him for “permission” to use him in this way he would vehemently deny this. His Christianity was MUCH closer to primitive Christianity than it was to Catholicism as practiced today. Mark my words on this. Catholics may quote Cyprian as authoritative, but Cyprian would hardly recognize modern Catholic Christianity with its purgatory, limbo, popes, indulgences, papal infallibility, Immaculate Conception, transubstantiation and many other such innovations.