The Long Afterlife of the New Testament Apocrypha: How the Canon Kept Growing After the Fourth Century

Many people imagine that the New Testament canon was decided all at once, perhaps when Athanasius of Alexandria sent out his Thirty-Ninth Festal Letter in 367 AD, listing the twenty-seven books we know today, or when the Councils of Hippo and Carthage confirmed that list in the late fourth century.

According to this view, the question of which books belonged was settled, and everything after that was just a matter of organization. However, the actual history is much more complicated: the canon did not simply close in the fourth century, and for centuries afterward, churches throughout the Mediterranean and Near East continued to copy, read, and even officially list several works that were not included in the final canon.

Some of these texts were even bound together with the Gospels and Epistles in important biblical manuscripts. Others were called Scripture by church authorities who claimed apostolic authority. Some continued to be used in worship and teaching long after the official lists had been set.

In this article, we will show how these texts continued to live after the canon was supposedly closed. We will identify the main “borderline” books that remained in church life from the fifth to the ninth centuries, examine the manuscripts and lists that included them, and explain why these books endured even as the canon became more fixed.

The Persistent Borderline Books

The Shepherd of Hermas

The Shepherd of Hermas is a good example of how the boundaries of the canon were not always clear. Written in Rome in the mid-second century, this apocalyptic and moral work became very popular as a teaching tool. Early church leaders such as Irenaeus and Clement of Alexandria regarded it as inspired.

Even after Athanasius and Jerome said it was only “useful for reading” and not truly part of Scripture, the Shepherd continued to be copied with the other biblical books. It appears in the canon list of the fifth-century Codex Claromontanus, right alongside the recognized New Testament books. The Muratorian Fragment, which scholars date to the late second century, also gives it a special place, recommending it for private reading but not for public worship.

The main reason for its survival was not theological debate, but its usefulness in teaching. Many Christians learned from its stories, and once a text becomes part of a community’s life, it is not easily set aside.

1 Clement and 2 Clement

The two letters known as 1 Clement and 2 Clement are important in this discussion because they were included in the fifth-century Codex Alexandrinus, one of the most significant biblical manuscripts. In this manuscript, both letters appear immediately after the book of Revelation, with nothing to indicate that they were considered different from the other books. For a reader in the fifth century, these letters would have looked just like Scripture.

1 Clement, written around 96 AD from the church in Rome to the church in Corinth, was even used in worship in some places into the sixth century. Because Clement was thought to be a disciple of Peter and Paul, his letter had a strong claim to authority.

2 Clement, which is actually an early Christian sermon and not by the same author, was often grouped with 1 Clement and later listed among “ecclesiastical” writings, even after it was no longer defended as Scripture.

The Didache

The Didache, also called the Teaching of the Twelve Apostles, is one of the earliest church manuals, probably written in the late first or early second century. It includes moral teachings as well as instructions on baptism, the Eucharist, fasting, and the organization of the church.

Athanasius, in his 367 letter, said the Didache was useful for teaching new believers, even though he did not include it as Scripture. This kind of endorsement helped the Didache stay in some Egyptian and Syriac lists of important books into the fifth century and later.

In some communities, the difference between “Scripture” and “important church document” was not always clear, so the Didache was accepted in both roles.

The Apocalypse of Peter

The Apocalypse of Peter is another example of a book that was considered for the canon, especially among apocalyptic writings. Its detailed descriptions of punishment and reward after death made it popular and hard to remove from church life.

It is included in the canon list of the fifth-century Codex Claromontanus. Later Byzantine writers sometimes mention that it was once read in churches, indicating that its status as Scripture was still remembered even after it was set aside.

The Apostolic Constitutions and the Apostolic Canons

One of the most notable examples of the canon expanding after the fourth century comes from the Eastern church. The Apostolic Constitutions, written in the late fourth century, is a collection of church rules and liturgy that claimed to come from the apostles.

Its eighty-fifth canon included a list of Scriptures that not only included the usual New Testament books but also named the two Clementine letters and even the Apostolic Constitutions themselves as canonical. This shows that some church leaders were still willing to add to the canon at this time.

Versions of this list were accepted in Greek and Syriac churches into the sixth century, and the Apostolic Canons continued to be used as church law in the Orthodox tradition, even after their scriptural list was no longer followed.

The Epistle of Barnabas

The Epistle of Barnabas is a second-century work that interprets the Hebrew Scriptures in a new way. It was included in the fourth-century Codex Sinaiticus, right alongside the New Testament books, with the Shepherd of Hermas after it.

Because it was copied in such important manuscripts and continued to circulate in Eastern churches into the fifth and sixth centuries, Barnabas remained closely connected to Scripture even after it was no longer officially defended as part of the canon.

Origen had called it a “catholic epistle,” and this reputation, along with its presence in major codices, helped keep its status as a borderline book.

The Canon Lists That Refused to Close

We can see how these books lasted by looking at the major biblical manuscripts and church lists from after the Council of Nicaea.

The fifth-century Codex Alexandrinus, as mentioned earlier, included the Clementine letters at the end of its New Testament. The Codex Claromontanus, also from the fifth century, included the Shepherd of Hermas, the Apocalypse of Peter, and Barnabas among its New Testament books. Canon 85 of the Apostolic Canons, dating to the late fourth or early fifth century, indicates that the Eastern church was willing to count the Clementines and the Apostolic Constitutions as Scripture.

Different Syriac and Coptic lists from the fifth to seventh centuries sometimes included the Didache, the Shepherd, or Barnabas as books suitable for reading in church, depending on the region and community.

It is important to see that these lists did not come from fringe groups or small sects. They were created by the main churches of Alexandria, Rome, Antioch, and Constantinople. This makes the point clear: the process of forming the canon took place over many centuries, not in a single decision.

Why the Borderline Held

There are several reasons why these books continued to be used long after Athanasius’s letter and the African councils. The first reason is regional diversity. The twenty-seven-book canon that Athanasius promoted in 367 was not accepted everywhere at once.

Local churches had their own traditions, worship practices, and ideas about which texts were important. They accepted the Athanasian list at different times. For example, Syriac Christians took centuries to accept some of the shorter letters and Revelation, and sometimes continued to use other books that Greek and Latin churches had already set aside.

Another reason is what we might call liturgical inertia. When a book is read in worship, used to teach new believers, or quoted in sermons, it becomes part of a community’s memory and practice. This is not easily changed by official decisions.

The Shepherd of Hermas and 1 Clement were both important in the worship life of large city churches, and their practical use lasted longer than the debates about whether they were inspired.

A third reason is the claim of apostolic origin. Whether these claims were real or just traditional, they gave the books a kind of authority that church leaders did not want to challenge.

1 Clement was believed to come from someone who knew the apostles. The Apostolic Constitutions and the Didache both said in their titles that they came from the apostles. Even when these claims were false, it was hard to remove a book that people believed was so connected after a few centuries.

Finally, the way manuscripts were put together also played a role. When scribes included the Shepherd, Barnabas, or the Clementine letters in the same book as the Gospels and Paul’s letters, it signaled to readers that these works belonged together.

Even if a church leader said that 1 Clement was not Scripture, someone reading the Codex Alexandrinus would see it right after the book of Revelation, looking just like the other books.

Conclusion

The story of the New Testament canon does not end in 367, 397, or even 419. Instead, it continued for several centuries, as churches in different regions slowly agreed on the twenty-seven-book list. At the same time, they continued to use some older works at the edges of their manuscripts and in their worship services.

The Shepherd of Hermas, the Clementine letters, the Didache, the Apocalypse of Peter, the Apostolic Constitutions, and the Epistle of Barnabas are more than just “almost canonical” texts. They show us how the canon really formed, not through a single decision, but through a long process involving church leaders, scribes, worship leaders, and ordinary believers, across many regions and centuries.

The line between Scripture and other important Christian writings stayed open much longer than we might expect.

Understanding this long afterlife does not weaken the authority of the canon, but helps us see its history more clearly. The twenty-seven books we have today are no less important because it took centuries to agree on them.

Instead, they are the result of a process that was slower, more complex, and more varied than we often think. The borderline books show us that the early church lived with uncertainty about the edges of its Bible for a long time, and that the final form of the New Testament was achieved only after much effort.