Concept

Canon

Q: How was the biblical canon decided?

The canon was recognized by the Church, not created by it: the NT books that emerged as canonical were apostolic in origin, used liturgically across the early Church, doctrinally consistent with the rule of faith, and self-evidencing through the Spirit's testimony to the believing community. Athanasius's 39th Festal Letter (367), Hippo (393), and Carthage (397) ratified what was already in use.

Intro

Why are there 66 books in the Bible (or 73 in a Catholic Bible), and not more or fewer? Who decided, and when? The popular answer, often heard from skeptics and from Dan Brown novels, is that Constantine and the Council of Nicea picked the books in the year 325 and threw away everything else. That story is not true.

The biblical books were not chosen by a vote at a council. They were recognized over centuries by the everyday use of churches across the Roman world, in the same way the scientific community recognized the laws of gravity without anyone needing to crown them. By the time any council made a formal list, the list mainly wrote down what Christians had already been reading and treating as Scripture for generations.

The criteria the early church used were simple. Was the book written by an apostle or a close associate of an apostle? Was it written early, in the first century? Did it agree with what the apostles taught? Was it used by churches everywhere, not just in one region?

The remaining differences between Protestant, Catholic, and Orthodox Bibles trace to a separate question about a smaller group of Old Testament books (the Apocrypha or Deuterocanon), which different traditions handle differently. The page below walks through the actual historical sequence.

In full

The biblical canon is the list of books recognized as divinely inspired Scripture. Protestants hold 66 books (39 OT + 27 NT); Roman Catholics hold 73 (adding the Deuterocanon, Tobit, Judith, Wisdom, Sirach, Baruch, 1-2 Maccabees, plus additions to Esther and Daniel); Eastern Orthodox holds 76+ (adding 1 Esdras, 3 Maccabees, Prayer of Manasseh, sometimes 4 Maccabees and Psalm 151); Ethiopian Orthodox extends further (Jubilees, 1 Enoch, etc.). The canon was not "imposed top-down" by Constantine or any council, it was recognized over centuries through the church's universal reception of texts that bore the marks of apostolic origin and Spirit-attestation.

Christian Position

Five classical criteria for canonical recognition (Beckwith, F.F. Bruce, R. Pache):

Apostolicity, written by an apostle or close apostolic associate (Mark with Peter, Luke with Paul).
Antiquity, composed within the apostolic period (1st century).
Orthodoxy, consistent with the apostolic regula fidei and prior Scripture.
Universal acceptance, received as Scripture across the geographic church, not just one region.
Inspiration recognition, the inner witness of the Spirit; "my sheep hear my voice" (John 10:27).

OT Canon

The OT canon was effectively closed by Jesus' time. Jesus refers to the threefold division, "the Law of Moses and the Prophets and the Psalms" (Luke 24:44), matching the Tanakh (Torah / Nevi'im / Ketuvim). Other "all the prophets, from Abel to Zechariah" (Luke 11:51) brackets the OT from Genesis (Abel) to 2 Chronicles (Zechariah son of Jehoiada), the Jewish canonical order, confirming a closed list. Josephus (Against Apion 1.8, c. 95 AD) lists 22 books matching the Protestant OT.

The "Council of Jamnia" (~90 AD) myth, long popularized as the moment Judaism closed its canon, has been thoroughly debunked (Jack Lewis, 1964; Lee McDonald). Jamnia was a rabbinic academy, not a canonical council; it debated only a few marginal books (Ecclesiastes, Song of Songs, Esther) already long-treated as Scripture.

NT Canon

AD 30-100, apostolic writings produced; 2 Pet 3:16 refers to Paul's letters as "Scripture."
c. 100 AD, Clement of Rome (1 Clement, c. 96), Ignatius, Polycarp cite most NT books as authoritative.
c. 140 AD, Marcion's truncated canon (Luke + 10 Pauline letters) forces the orthodox church to articulate its own list.
c. 170 AD, Muratorian Fragment lists 22+ NT books recognized at Rome; missing only Hebrews, James, 1-2 Peter.
c. 200 AD, Tertullian, Clement of Alexandria, Origen treat 20+ books as authoritative; debate persists on Hebrews, James, 2 Peter, 2-3 John, Jude, Revelation ("antilegomena", disputed).
AD 325, Council of Nicea: does NOT canonize anything (contrary to popular myth); deals with Arianism.
AD 367, Athanasius' Festal Letter 39: first surviving list of exactly the 27 NT books we have today.
AD 393 / 397 / 419, Councils of Hippo and Carthage: ratify the 27-book NT (and a broader OT including the Deuterocanon).

Common Objection / Skeptical Position

Three skeptical lines:

"Constantine picked the books at Nicea (325 AD), suppressed the others", popularized by Dan Brown's Da Vinci Code and parroted across atheist forums.
"There are 'lost gospels' (Thomas, Judas, Mary) that should have been included", the Gnostic / Nag Hammadi corpus.
"The Catholic Apocrypha is in or out arbitrarily", why did Protestants drop seven books?

Response

Constantine and Nicea: Nicea (325 AD) decided no canonical question. The earliest list of the 27 NT books is Athanasius' Festal Letter (367 AD), 30 years after Nicea, and Athanasius was reflecting widespread existing practice. The NT canon was de-facto settled centuries earlier by universal reception in liturgy, citation, and copying. Constantine sponsored 50 Bible copies for Constantinople (Eusebius, Life of Constantine 4.36), but this means the canon was already known, not that he chose it.
Gnostic gospels (Thomas, Judas, Mary, Philip), written 2nd-4th c., long after the apostolic period, in Coptic translations from lost Greek originals, theologically incompatible with the apostolic gospel (anti-material, esoteric, often anti-Jewish in a Marcionite sense). They fail criteria 1, 2, and 3. The early church did not "suppress" them, it never received them.
Deuterocanon / Apocrypha: the Jewish OT (Tanakh) does NOT include these books; they are present in the Septuagint (LXX) but with secondary status. Jerome, translating the Vulgate (c. 400 AD), distinguished libri ecclesiastici (good for edification) from libri canonici (canonical), and placed the Deuterocanon in the former category. Augustine disagreed and favored their inclusion. The Council of Trent (1546) formally canonized them in Catholicism in reaction to Reformation challenges. The Reformers (Luther, Calvin) followed Jerome and the Jewish canon, hence 66 books.

The canon was not "decided", it was recognized. As B.B. Warfield put it: "the Church no more gave us the New Testament canon than Sir Isaac Newton gave us the force of gravity."

Key Passages

Luke 24.44, "the Law of Moses and the Prophets and the Psalms", threefold OT division.
(2 Tim 3:16, NASB95), "all Scripture is inspired by God", presupposes a recognized body.
(2 Pet 3:15-16, NASB95), Paul's letters classed with "the rest of the Scriptures."
(John 10:27, NASB95), "My sheep hear My voice", the Spirit-attestation criterion.

Inerrancy, what Scripture is; canon is which Scripture.
Manuscripts, how the canonical books reach us.
Inspiration, why the canonical books bear authority.
Didache, late-1st / early-2nd c. document that quotes NT material but was not received as Scripture; useful test case.
Sola Scriptura, Protestant principle of Scripture's final authority.

Common questions this page answers

Q: How was the biblical canon decided?

The canon was recognized by the Church, not created by it: the NT books that emerged as canonical were apostolic in origin, used liturgically across the early Church, doctrinally consistent with the rule of faith, and self-evidencing through the Spirit's testimony to the believing community. Athanasius's 39th Festal Letter (367), Hippo (393), and Carthage (397) ratified what was already in use.