The canon — the fixed, authoritative list of books considered scripture — was not decided in one moment by one council. It was a centuries-long, often contentious process shaped by theology, but also by politics, geography, and the outcomes of power struggles between rival Christian factions.
The Hebrew Bible's three-part structure — Torah, Nevi'im, Ketuvim, together the Tanakh — was largely settled by roughly 200 CE. A common reference point is the so-called Council of Jamnia (~90 CE), where rabbis reportedly debated which books "defiled the hands," a phrase referring to canonical status. Modern scholars are divided on how decisive that meeting actually was; it may have ratified an existing consensus rather than created one.
The most contested books in the Hebrew canon were Song of Songs (sacred text or love poetry?), Ecclesiastes (its skepticism troubled some rabbis), and Esther (it never mentions God at all).
Jewish communities in Alexandria, around 250 BCE, translated the Hebrew scriptures into Greek — the Septuagint (LXX). This translation included additional books not present in the Hebrew canon: Tobit, Judith, 1 and 2 Maccabees, Sirach, Wisdom of Solomon, and Baruch.
These became known as Deuterocanonical books to Catholics and Orthodox Christians, and Apocrypha to Protestants. The split traces to Jerome (~400 CE), who preferred the Hebrew canon for his Latin Vulgate translation, and later to Luther (1520s), who removed them from Protestant Bibles entirely — partly because Catholics used 2 Maccabees to support the doctrine of purgatory.
Early Christians overwhelmingly used the Septuagint, not the Hebrew text. That's why many New Testament quotations of the Old Testament match the Greek LXX rather than the Hebrew original — a detail that matters for anyone tracing a quotation back to its source.
One persistent myth deserves correction immediately: the Council of Nicaea (325 CE) did not decide the New Testament canon. Nicaea addressed the Arian controversy — the nature of Christ's divinity — not which books belonged in scripture. The canon process was slower and more diffuse than that.
Early church leaders weighed four tests when debating which texts belonged: apostolicity (was it written by an apostle or close associate), orthodoxy (did it align with accepted teaching), catholicity (was it used widely across churches), and antiquity (was it old enough to plausibly be apostolic). The honest problem is that these criteria were frequently applied retroactively, to justify books already favored rather than to neutrally adjudicate disputed ones.
| Date | Event | Significance |
|---|---|---|
| ~140 CE | Marcion's canon | First defined Christian canon — 10 Pauline letters and an edited Luke, rejecting the Old Testament entirely. Declared heretical, but forced the orthodox church to define its own list in response. |
| ~180 CE | Irenaeus | Argued forcefully for exactly four Gospels — no more, no less. |
| ~300 CE | Eusebius's categories | Sorted texts into "recognized," "disputed," and "rejected" — Revelation sat uneasily in the disputed column. |
| 367 CE | Athanasius's Easter Letter | First time in history the exact 27 books we use today appear together as a list. |
| 397 CE | Council of Carthage | Formally ratified the 27-book canon, though regional debate continued for generations after. |
Many widely-read early Christian texts were ultimately excluded. The Gospel of Thomas was excluded largely for its Gnostic theology and lack of narrative structure. The Gospel of Peter implied Jesus didn't genuinely suffer (a view called Docetism). The Shepherd of Hermas was widely respected but considered too recent and not apostolic. The Didache was treated as a practical manual rather than scripture.
The Gnostic texts discovered at Nag Hammadi in 1945 dramatically expanded what we know about this excluded material — showing these weren't fringe documents but texts genuinely used by real Christian communities.
The canon reflects spiritual discernment, but also power and geography. Books favored by influential centers — Rome, Alexandria, Antioch — had a structural advantage. Books associated with theologically losing factions — Gnostics, Marcionites, Ebionites — were excluded, and in many cases their texts were actively destroyed. As the scholar Bart Ehrman frames it: the winners wrote the history, and the winners chose the canon. That's not a dismissal of the canon's value — but it is an accurate description of the process that produced it.
Both the Old and New Testament canons emerged gradually, through a mix of genuine theological discernment and real institutional power. Neither canon was a single decree from a single authority. Different Christian traditions today — Catholic, Orthodox, Protestant — still don't fully agree on the list, which is itself evidence that the process was never as settled as it's often presented.