How Many Books Are in the Bible?

Understanding Psalm 119:105

The answer depends on which Christian tradition you ask — and understanding why reveals important history about how the Bible was formed.

The Protestant Bible: 66 books.

• Old Testament: 39 books (Genesis through Malachi)
• New Testament: 27 books (Matthew through Revelation)

This is the Bible used by most evangelical, Baptist, Methodist, Presbyterian, Lutheran, and non-denominational churches.

The Catholic Bible: 73 books.

The Catholic Bible includes the same 66 books plus 7 additional Old Testament books known as the Deuterocanon (meaning 'second canon'):

1. Tobit — A story of faith, family, and angelic intervention
2. Judith — A heroine who saves Israel from an invading army
3. 1 Maccabees — The history of the Maccabean revolt (167-134 BC)
4. 2 Maccabees — A theological interpretation of the same period
5. Wisdom of Solomon — A wisdom text attributed to Solomon
6. Sirach (Ecclesiasticus) — Practical wisdom similar to Proverbs
7. Baruch — A letter attributed to Jeremiah's scribe

The Catholic Bible also includes additions to the books of Esther and Daniel that are not in the Protestant versions.

The Orthodox Bible: 76-81 books.

Eastern Orthodox churches include the Catholic deuterocanonical books plus additional texts such as 1 Esdras, 3 Maccabees, the Prayer of Manasseh, and Psalm 151. The Ethiopian Orthodox Church has the largest canon of any Christian tradition, with 81 books.

Why the difference?

The core issue is the status of Jewish writings composed between roughly 300 BC and 100 BC — the period between the Old and New Testaments.

The Jewish canon. By the end of the 1st century AD, Jewish authorities recognized 24 books as Scripture (which correspond to the 39 Protestant Old Testament books — the difference in number is because Jews count some books together that Protestants separate). These books were all written in Hebrew or Aramaic.

The Septuagint (LXX). When the Hebrew Bible was translated into Greek (beginning around 250 BC), the translators included additional Jewish writings that were widely read but not part of the Hebrew canon. The early Christian church — which used Greek — inherited this broader collection. The New Testament itself quotes from the Septuagint frequently.

The early church was divided. Some church fathers (like Augustine) considered the deuterocanonical books to be Scripture. Others (like Jerome, who translated the Latin Vulgate) accepted them as useful for edification but not as the basis for doctrine. This debate continued for over a thousand years without formal resolution.

The Reformation. Martin Luther, following Jerome's position, removed the deuterocanonical books from the Old Testament and placed them in a separate section between the Testaments, calling them the 'Apocrypha' — useful to read but not equal to Scripture. Over time, most Protestant Bibles dropped them entirely.

The Council of Trent (1546). In response to the Reformation, the Catholic Church formally defined the deuterocanonical books as fully canonical Scripture. This was not a new decision — it affirmed what had been the majority practice for centuries — but it was the first time it was officially dogmatized.

What all Christians agree on.

All major Christian traditions — Protestant, Catholic, and Orthodox — agree on the 27 books of the New Testament and the core 39 books of the Old Testament. The disagreement is only about the deuterocanonical/apocryphal books.

Regardless of which canon a Christian follows, the message of the Bible is consistent: God created humanity, humanity fell into sin, God initiated a plan of redemption through Israel, fulfilled it in Jesus Christ, and will one day restore all things. That narrative arc is present in 66 books, 73 books, or 81 books.

How the books were chosen.

The Bible was not assembled by a single committee at a single meeting. The process of recognizing which books were authoritative (called 'canonization') happened organically over centuries. The criteria included:

1. Apostolic origin or connection — Was it written by an apostle or someone closely associated with an apostle?
2. Orthodoxy — Did its teaching align with the established faith of the church?
3. Catholicity — Was it widely accepted and used across multiple churches?
4. Traditional use — Had the church been reading it in worship for generations?

The church did not create the canon — it recognized it. The books that made it into the Bible did so because the church, guided by the Holy Spirit, recognized them as having the inherent authority of God's Word.