What “canon” means
A canon is an accepted list of writings that a community treats as authoritative scripture. The word comes from a Greek term for a measuring rule. Different religious communities have different canons, and even within Christianity the lists are not identical.
Understanding that the canon developed over time is the first step in reading claims about it. There was no single moment when one authority published a final list for everyone.
The earliest Christian writings
The letters attributed to Paul are generally dated to the middle of the first century, and the four Gospels to the decades after. These texts circulated among communities, were copied and read aloud in worship, and were quoted by later writers.
Early Christians also used other writings that did not become part of the New Testament. Some communities valued texts that others did not, and local practice varied from city to city.
Early lists and the fourth century
Several early documents list books that a writer considered authoritative. One example is the Muratorian fragment, a damaged list whose date is debated by scholars. Church leaders such as Origen and Eusebius also discussed which books were widely accepted and which were disputed.
In 367 CE, Athanasius of Alexandria sent a festal letter that lists the twenty-seven books of the New Testament as Christians commonly know them today. It is the earliest surviving list that matches the modern New Testament exactly, though it represents one bishop’s guidance, not a decision binding on everyone.
Regional councils and later decisions
Regional councils in North Africa, such as those held at Hippo in 393 and Carthage in 397, endorsed similar lists. Over the following centuries the same twenty-seven books became standard across most of Christianity.
The Hebrew Bible and the Old Testament also differ by tradition. The Catholic Church formally affirmed its list of Old Testament books at the Council of Trent in the sixteenth century, and Orthodox churches include additional books. Protestant traditions use a shorter Old Testament list.
Questions worth asking
When you read about a “lost” or “suppressed” book, ask which community used it, how early the evidence for its use is, and why later communities did or did not adopt it. These questions replace a single dramatic story with a more careful picture.
The history of the canon shows real disagreement, regional differences and slow consensus. That is more complicated than a conspiracy account, and it is better supported by the surviving documents.