The 66 Books of the Bible: A Simple Overview

Pick up a Protestant Bible and check the contents page: you will count 66 books. That number is worth understanding, because the 66 books of the Bible are not an arbitrary total. They represent 39 books inherited from the Hebrew Scriptures and 27 books recognized by the early Christian church, and the count varies in other Christian traditions for reasons that make good historical sense.

Why Protestant Bibles Contain 66

The 39 Old Testament books match the contents of the Hebrew Bible, though Jewish tradition counts them as 24 by combining several (the twelve Minor Prophets are one scroll, for instance). The 27 New Testament books were settled by the fourth century. A useful definition of what is going on here comes from biblical scholar Edmon Gallagher, who argues that a canon is best understood as the collection a community regards as carrying binding authority, evidenced above all by the lists ancient believers actually wrote down.

The Old Testament’s 39, Quickly

• Law (5): Genesis, Exodus, Leviticus, Numbers, Deuteronomy. Origins, exodus, and covenant law.
• History (12): Joshua, Judges, Ruth, 1 and 2 Samuel, 1 and 2 Kings, 1 and 2 Chronicles, Ezra, Nehemiah, Esther. Conquest, monarchy, exile, and return.
• Wisdom and Poetry (5): Job, Psalms, Proverbs, Ecclesiastes, Song of Songs. Suffering, prayer, practical wisdom, doubt, and love.
• Major Prophets (5): Isaiah, Jeremiah, Lamentations, Ezekiel, Daniel. Named “major” for length, not importance.
• Minor Prophets (12): Hosea through Malachi. Short, sharp books, many focused on justice and covenant faithfulness.

The New Testament’s 27, Quickly

• Gospels (4): Matthew, Mark, Luke, John.
• History (1): Acts, the story of the first churches.
• Pauline Letters (13): Romans through Philemon, addressed to congregations and to individuals such as Timothy and Titus.
• General Letters (8): Hebrews, James, 1 and 2 Peter, 1 to 3 John, Jude.
• Apocalypse (1): Revelation.

The letters, not the Gospels, are the oldest documents here. Paul was writing to churches in the 50s of the first century, roughly two decades before the first Gospel was likely written down. Yale’s Dale Martin traces how this material moved from scattered stories and letters into a recognized collection over several centuries, a process that was gradual and regionally uneven rather than decided in a single moment.

Why Some Bibles Count More Than 66

This is where readers often get confused, and there is nothing sinister about it. Catholic Bibles contain 73 books, adding seven to the Old Testament: Tobit, Judith, Wisdom, Sirach, Baruch, and 1 and 2 Maccabees, along with additional sections of Esther and Daniel. The United States Conference of Catholic Bishops lists these books as part of the Old Testament canon. Catholics call them deuterocanonical, meaning a second stage of the canon rather than second-rate.

Eastern Orthodox Bibles include those books and several more, such as 3 Maccabees, 1 Esdras, and Psalm 151. The differences trace back to which ancient collection a tradition followed. The Greek Septuagint, widely used by early Greek-speaking Christians, included these writings; the Hebrew collection used in Palestinian Judaism did not. Protestant reformers in the sixteenth century chose to align the Old Testament with the Hebrew list, which is why most Protestant Bibles print 66.

What This Means for Reading

Three things are worth holding onto. First, the disagreement concerns a limited set of Old Testament books; all major traditions accept the same 27 New Testament books. Second, the disputed writings were never hidden or suppressed, and many Protestant Bibles have historically printed them in a separate section for their historical value. Third, no core Christian doctrine rests solely on the disputed books.

If you are new to reading, the count is background information rather than a hurdle. Whatever edition you hold, the main storyline runs the same way from Genesis to Revelation.