Why do Catholic Bibles have more books than Protestant Bibles?

Pick up a Catholic Bible and a Protestant Bible side by side, and you will notice the Old Testament sections do not quite match. The Catholic Old Testament contains several additional books and passages that Protestant Bibles leave out entirely. This is one of the most common questions people ask when comparing different Christian Bibles, and the answer lies in real historical events, not arbitrary preference.

Both traditions share the same New Testament and agree on far more than they disagree on regarding the gospel of Jesus Christ. The difference concerns a specific set of Old Testament-era Jewish writings and how much authority they deserve.

The additional books Catholic Bibles include are Tobit, Judith, Wisdom, Sirach, Baruch, and 1 and 2 Maccabees, along with extra material added to Esther and Daniel. Catholics call these books “deuterocanonical,” meaning “belonging to a second canon,” reflecting their somewhat later and more contested acceptance compared to the rest of the Old Testament.

These books were written during the roughly four-hundred-year period between the Old Testament prophet Malachi and the birth of Christ, a time widely regarded, even within Judaism itself, as one in which prophetic revelation had ceased, as the book of 1 Maccabees itself acknowledges directly.

These books appeared in the Septuagint, the Greek translation of the Hebrew Scriptures widely used by Greek-speaking Jews and by many early Christians, since most of the earliest church was Greek-speaking. Because these additional writings circulated alongside the Hebrew Scriptures in some Greek manuscript traditions, they gained a level of familiarity and use within parts of the early church.

However, the original Hebrew Scriptures used in Judea, the same Scriptures Jesus and the apostles referenced, never included these books. Jerome, the great fourth-century scholar who translated the Bible into Latin, insisted on this distinction, calling the disputed books useful for edification but not authoritative for establishing doctrine, even while including them in an appendix to his translation.

For over a thousand years after Jerome, the Western church held a somewhat ambiguous position on these books, often using them liturgically while several respected theologians, from Jerome through the Middle Ages, continued to flag their secondary status. The matter came to a head during the Protestant Reformation.

Martin Luther and other Reformers, examining Scripture in its original languages, removed these books from the Old Testament proper, following Jerome's earlier Hebrew-canon standard, and relegated them to a separate section. In response, the Catholic Church formally declared these books canonical Scripture at the Council of Trent in 1546, partly to settle the question decisively against the Reformers' position.

Protestants find the case for exclusion more historically and theologically compelling. The books were never part of the Hebrew canon that Jesus affirmed (Luke 24:44), no New Testament writer ever quotes them as Scripture, and their own content sometimes conflicts with clear biblical teaching, as when 2 Maccabees commends prayer for the dead to atone for sin, in tension with the Bible's teaching on judgment after death (Hebrews 9:27).

Catholics, meanwhile, appeal to the books' long liturgical use and the authority of church tradition to settle disputed questions of canon. Both sides agree these books have historical value; they disagree about whether long use and church tradition are sufficient grounds for elevating a book to the same authoritative status as Scripture recognized by Jesus himself.

It is worth remembering what this disagreement is not about. It is not a disagreement over the gospel itself, that salvation comes through Jesus Christ, or over the identity of Christ as fully God and fully man. Faithful believers across both traditions affirm these central truths together.

The difference concerns the proper boundaries of the Old Testament canon, a real and important question, but one that should be studied with humility rather than hostility. For the Protestant reader, the conviction remains that the thirty-nine-book Old Testament Jesus himself affirmed is “useful for teaching, rebuking, correcting and training in righteousness” (2 Timothy 3:16), complete and sufficient without addition.

If you find yourself in conversation with a Catholic friend about this difference, it can be discussed with genuine warmth rather than suspicion. You can acknowledge the real history behind the disagreement, explain why you hold the position you do, and still recognize a brother or sister who shares your confession that Jesus Christ is Lord and Savior.