Why does a Catholic Bible have 73 books, and a Protestant Bible only have 66 books? Well, it was the Catholic Church that was given the authority by Christ to decide which books were inspired and belonged in the Bible. The Holy Spirit guided the Catholic Church over time to recognize and determine the canon of the New and Old Testaments in the year 382 at the synod of Rome, under Pope Damasus I. This decision was ratified again at the councils of Hippo (393) and Carthage (397 and 419). Today we find that both Catholics and Protestants have 27 books that make up the New Testament. So, the difference comes from the number of books that make up the Old Testament.
What the Catholic Church teaches:
“It was by the apostolic Tradition that the Church discerned which writings are to be included in the list of the sacred books. This complete list is called the canon of Scripture. It includes 46 books for the Old Testament (45 if we count Jeremiah and Lamentations as one) and 27 for the New.” (Catechism of the Catholic Church #120)
“…The Church from the very beginning accepted as her own that very ancient Greek [Septuagint] translation of the Old Testament which is named after seventy men…” (Vatican II document, Dei Verbum, #22)
It is understandable that a Catholic might be asked by a Protestant why the difference? That person would say that the Bible clearly says that we are not to add to Scripture; “God will add to him the plagues described in this book” (Rev. 22:18). They would ask “why did Catholics add seven books to the Old Testament?” Well, if you read the next verse, it says that one should not take away from the Scriptures; “…if anyone takes away from the words in this prophetic book, God will take away his share in the tree of life and in the holy city described in this book” (Rev. 22:19). So, the question that could be asked is, “why did Martin Luther and the Protestant reformers take away seven books from the well established canon of Scripture?”
In the early Church, most Christians spoke Greek. So, the twenty-seven books of the New Testament were written in Geek, a language they could understand. In the time of Christ and the early Church, they used a Greek translation of the Jewish Scriptures (Old Testament) that they called the Septuagint.
Historian and Scripture scholar Jerome Kodell writes:
“…Besides the 39 [Old Testament] books revered as inspired by Protestant Christians (and Jews), Catholics include seven additional books: Baruch, Judith, 1 Maccabees, 2 Maccabees, Sirach (Ecclesiasticus), Tobit, and Wisdom…These books are known by Catholics as ‘deuterocanonical’ and by Protestants as ‘The Apocrapha’…
…The current differences among Christians stem from the unsettled state of the Jewish scriptural canon in the early days of the [Christian] Church. A final decision on the contents of the Old Testament was not made in Judaism until the second or third century after Christ…” (Jerome Kodell, O.S.B., The Catholic Bible Study Handbook, pp. 41-44)
John McKenzie, S.J., in his book, Dictionary of the Bible writes:
“The [Septuagint] enjoyed great authority among the Jews of the Diaspora into the 1st century A.D. It was the Gk Bible, and for this reason it was adopted by Christians when they began to evangelize the Hellenistic world. Christians adopted with even greater enthusiasm than the Jews; it became the Bible of the Church in the first generation of Christians, and 300 of the 350 citations from the Old Testament in the New Testament are quoted according to the [Septuagint]…There is little doubt that the acceptance of the [Septuagint] and its use by Christians led the Jews to reject it…From the time of Paul onwards there can be little doubt that the [Septuagint], with the deuterocanonical books, was the OT of the apostolic church; it was probably adopted because Greek was the common language of the Mediterranean lands.”
In the second century, the Jewish leaders at the time, rejected seven of the books that were considered part of the Septuagint on the grounds that they could not find any Hebrew versions of these books. Their version of the Old Testament is called the Palestinian canon. In 1529, Martin Luther choose to accept the Palestinian canon. So, that is why Catholic Bibles are bigger than Protestant Bibles. Well, until next time, God bless.