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Who Decided Which Books Went Into the Bible?

No single council decided it. The canon emerged from use across centuries: by about 200 CE the four Gospels and Paul’s letters were already read as scripture in scattered churches, and Athanasius’ festal letter of 367 CE gives the first surviving list of exactly the 27 New Testament books. The synods of Hippo (393) and Carthage (397) ratified existing practice. Nicaea (325) did not decide the canon.

A process, not a decision

The word "decided" fits the history badly. What happened over roughly three centuries is that some texts were read aloud in worship, copied, and cited as authoritative, and others were not — and lists were written afterwards to describe what had already settled. John Barton’s A History of the Bible (2019) and Bruce Metzger’s The Canon of the New Testament (1987) both frame it this way: reception first, formalisation later.

Two pressures sharpened the process. Around 144 CE Marcion of Sinope promoted a deliberately narrow collection — an edited Luke and ten Pauline letters — and rejected the Hebrew scriptures; the reaction against him pushed other churches to say what they did accept. And around 180 CE Irenaeus of Lyon argued in Against Heresies that there could be four Gospels and no more. The Muratorian Fragment, a Latin list usually dated to around 170–200 CE (though some scholars argue for the fourth century), already contains most of what would become the New Testament.

The lists that survive

Around 325 CE Eusebius of Caesarea, in the Ecclesiastical History, sorted the books into categories: those universally recognised, those disputed (antilegomena — James, Jude, 2 Peter, 2 and 3 John), and those he regarded as spurious. He is describing a spectrum of acceptance, not issuing a ruling.

In 367 CE Athanasius of Alexandria sent his thirty-ninth festal letter, the annual circular announcing the date of Easter, and included a list of scripture. It names exactly the 27 books of the New Testament as they stand today — the first surviving document to do so. The North African synods of Hippo in 393 and Carthage in 397 then affirmed a canon matching that practice for the churches under their reach. None of these acts created the collection; each recorded one.

The early Christian writers doing the arguing can be read directly: the Apostolic Fathers — Clement of Rome, Ignatius, Polycarp and others, the generation immediately after the apostles — are available free at openscriptorium.com/books/apostolic.

The Nicaea myth, named plainly

The Council of Nicaea in 325 CE did not decide the biblical canon. Its business was the Arian controversy over the relationship of the Son to the Father, the date of Easter, and a set of disciplinary canons; no surviving act, canon, or contemporary account of the council contains a list of scripture. The picturesque version — books piled on an altar, the spurious ones falling off — comes from a much later legend, the ninth-century Synodicon Vetus, and has been recycled by modern popular fiction. Historians of every persuasion treat it as fiction.

Why canons still differ, and where Enoch went

There is no single Christian canon today. Catholic and Eastern Orthodox Bibles include deuterocanonical books — Tobit, Judith, Wisdom, Sirach, Baruch, 1–2 Maccabees and additions to Daniel and Esther — that circulated in the Greek Septuagint tradition; Jerome, translating the Vulgate in the late fourth century, expressed reservations about them, and Protestant Bibles after the Reformation either omitted them or printed them in a separate section. The Council of Trent defined the Catholic list in 1546. Orthodox canons vary further. These books can be read free at openscriptorium.com/books/apocrypha.

1 Enoch is the most-asked-about absence. It was well known — the letter of Jude quotes it directly (Jude 14–15), and Aramaic fragments of it were found among the Dead Sea Scrolls — but it was never widely received as scripture by Jewish or by most Christian communities, and so it simply never entered most canons. It was not thrown out at a council; it was never in. It is, however, canonical in the Ethiopian Orthodox Tewahedo tradition, which preserved the complete text in Ge‘ez when the Greek and Aramaic versions were lost.

On the Hebrew Bible side, an older textbook claim that a "Council of Jamnia" around 90 CE closed the Jewish canon has been abandoned. Jack P. Lewis’ 1964 article dismantled it, and the field now describes a gradual consolidation rather than a convening body.

What most scholars accept, and what stays contested

Frequently asked questions

Did the Council of Nicaea decide which books are in the Bible?

No. The council of 325 CE dealt with the Arian controversy, the dating of Easter, and disciplinary matters; no surviving act or contemporary account of it lists books of scripture. The story of books being piled on an altar so the spurious ones fell off comes from the ninth-century Synodicon Vetus, long after the event, and historians treat it as legend.

Why is the Book of Enoch not in the Bible?

1 Enoch was widely known — the letter of Jude quotes it, and Aramaic fragments were found among the Dead Sea Scrolls — but it was never received as scripture by most Jewish or Christian communities, so it never entered their canons rather than being removed from them. It is canonical in the Ethiopian Orthodox Tewahedo tradition, which preserved the complete text in Ge‘ez.

Why do Catholic and Protestant Bibles contain different books?

Catholic and Orthodox Bibles include deuterocanonical books such as Tobit, Judith, Wisdom, Sirach and 1–2 Maccabees, which circulated in the Greek Septuagint tradition. Jerome voiced reservations about them in the late fourth century, and Reformation-era Protestant Bibles either omitted them or set them apart as Apocrypha. The Council of Trent defined the Catholic list in 1546.

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