The Canon

“The words of the LORD are pure words, like silver refined in a furnace on the ground, purified seven times.” — Psalm 12:6

How do we know which books belong in the Bible? The word kanōn (κανών) — “rule, standard, measuring reed” — came to designate the collection of books recognized as divinely inspired Scripture. The canon is not a list the church invented but a reality the church discerned: God gave His Word, and His people recognized it. For how this authority and inspiration function, see the companion articles.

The Principle of Recognition

A crucial distinction: the church did not confer authority on certain books by including them in a list. Rather, the books carried inherent divine authority from the moment they were written, and the church, guided by the Holy Spirit, progressively recognized that authority.

As J.I. Packer put it, “The church no more gave us the canon than Sir Isaac Newton gave us the force of gravity.” The canon was recognized, not imposed.

The Old Testament Canon

Torah

The five books of Moses were accepted as authoritative from the earliest period of Israel’s history. Moses himself wrote and deposited the Law beside the ark of the covenant (Deuteronomy 31:24–26), and subsequent biblical authors treated it as the foundational Word of God (Joshua 1:8; 2 Kings 22:8–13).

Prophets

The prophetic writings were received as authoritative as they were written. Daniel read Jeremiah as Scripture (Daniel 9:2). By approximately 200 BC, the collection of the Prophets (Nevi’im) was widely recognized, as evidenced by the prologue to Sirach (c. 132 BC), which refers to “the Law and the Prophets and the other books.”

Writings

The Ketuvim were the last division to reach a settled consensus. Later rabbinic discussions (sometimes associated with a supposed council at Yavneh/Jamnia, c. 90 AD) debated the status of books like Ecclesiastes, Song of Solomon, and Esther. Modern scholars increasingly question whether a formal “council” ever occurred at Yavneh; the rabbinic discussions there were likely informal debates rather than an authoritative decree. In any case, these discussions were more about confirming what was already received than about making new decisions.

Jesus Himself referred to the entire Hebrew canon as “the Law of Moses and the Prophets and the Psalms” (Luke 24:44), indicating that the three-fold division was recognized in His day.

The Septuagint and the Deuterocanonical Books

The Septuagint (LXX) — the Greek translation of the Old Testament produced in Alexandria beginning around 250 BC — included additional books not found in the Hebrew canon: Tobit, Judith, Wisdom of Solomon, Sirach (Ecclesiasticus), Baruch, 1–2 Maccabees, and additions to Daniel and Esther.

The status of these books has been a point of longstanding disagreement among Christians:

• Roman Catholics (following the Council of Trent, 1546) regard them as deuterocanonical — fully inspired and authoritative, a “second canon” alongside the protocanonical books. The Catholic Old Testament thus contains 46 books (compared to the Protestant 39).
• Eastern Orthodox churches generally accept most of these books as canonical, with some variation among national churches, and may include additional texts such as 3 Maccabees, Psalm 151, the Prayer of Manasseh, and 1 Esdras.
• Protestants classify them as apocryphal — valuable for historical and devotional reading but not the basis for doctrine. The Reformers noted that these books were not part of the Hebrew canon, were not quoted as Scripture by Jesus or the apostles, and contain material in tension with the rest of the canon.

The New Testament Canon

The formation of the New Testament canon was guided by several criteria:

1. Apostolicity — Was the book written by an apostle or a close associate of an apostle (e.g., Mark with Peter, Luke with Paul)?
2. Orthodoxy — Was the book’s teaching consistent with the apostolic faith already received?
3. Catholicity — Was the book widely accepted and used across the churches, not merely in one region?
4. Liturgical usage — Was the book read in public worship as Scripture?

The core of the New Testament — the four Gospels and Paul’s major epistles — was universally acknowledged from the earliest period. A few books (Hebrews, James, 2 Peter, 2–3 John, Jude, Revelation) were debated in some regions before reaching universal acceptance.

Athanasius’ 39th Festal Letter (367 AD)

The earliest extant list that matches the 27-book New Testament (recognized by all major Christian traditions) comes from Athanasius, Bishop of Alexandria, in his 39th Festal Letter of 367 AD. He listed exactly the 27 books we have today, calling them the “springs of salvation.” The councils of Hippo (393) and Carthage (397) subsequently ratified this list — not creating the canon but formally recognizing what the churches had already received.

The Canon as God’s Gift

The canon is ultimately a matter of God’s providence. The same God who inspired the Scriptures also preserved them and guided His people to recognize them. The canon is not a fragile human construction but a pillar of God’s sovereign care for His Church — that she might have His Word, whole and complete, until Christ returns.

“Heaven and earth will pass away, but my words will not pass away.” — Matthew 24:35