Question: What's the difference between a Catholic Bible and a Protestant one? Is our Old Testament the same as a Jewish Bible? If not, why?
Discussion: The most noticeable differences occur in the number of books included and the order in which they have been arranged. Both the Jewish Bible and the Hebrew canon in a Protestant Bible (aka Old Testament) contain 39 books, whereas a Catholic Bible contains 46 books in the Old Testament. In addition, the Greek Orthodox, or Eastern Orthodox, Church accepts a few more books as canonized scripture.
To give you a quick overview of a complicated subject, here's what happened: Several hundred years before the birth of Christ, Babylonian conquerors forced the Jews to leave Jerusalem. Away from their Temple and, often, from their priests, the exiled people forgot how to read, write, and speak Hebrew. After a while, Jewish scholars wanted to make the Bible accessible again, so they translated Hebrew scriptures into the Greek language commonly spoken. Books of wisdom and histories about the period were added, too, eventually becoming so well known that Jesus and the earliest Christian writers were familiar with them. Like the original Hebrew scriptures, the Greek texts, which were known as the Septuagint, were not in a codex or book form as we're accustomed to now but were handwritten on leather or parchment scrolls and rolled up for ease in storage.
Eventually, the Jewish exiles were allowed to return to Jerusalem where they renovated the Temple. Then, in A.D. 70, warring peoples almost completely destroyed the sacred structure, which has never been rebuilt. Without this central place of worship, the Jews began looking to the Bible as their focal point of faith, but to assure the purity of that faith, only Hebrew scriptures were allowed into the Jewish canon. By then, however, the earliest Christians spoke and read Greek, so they continued to use the Septuagint or Greek version of the Bible for many centuries. After the Reformation though, some Christians decided to accept translations into Latin then English only from the Hebrew texts that the Jewish Bible contained, so the seven additional books in the Greek translation became known as the Apocrypha, meaning "hidden." Since the books themselves were no secret, the word seemed ironic or, perhaps, prophetic because, in 1947, an Arab boy searching for a lost goat found, instead, the Dead Sea scrolls, hidden in a hillside cave.
Interestingly, the leather scrolls had been carefully wrapped in linen cloth, coated in pitch, and placed in airtight pottery jars about ten inches across and two feet high where, well-preserved, they remained for many centuries. Later, other caves in the same area yielded similar finds with hundreds of manuscripts no longer hidden. Indeed, the oldest copies of the Bible now known to exist are the Dead Sea scrolls of the Septuagint.
Because of this authentic find from antiquity, many publishers in the twentieth century added back the books of Tobit, Judith, Wisdom, Ecclesiasticus, Baruch, First and Second Maccabees, as well as additions to Esther and Daniel. So now, when an edition of the Bible says "with Apocrypha" on the cover, the extra books from the Septuagint will usually be placed between the Old and New Testaments or at the end of the Bible. Catholic Bibles already contained those books, however, so you'll find them interwoven with other Old Testament books of history and wisdom writings.
For the New Testament, it's a different story — and short. All of the books were written in Greek or Aramaic from the start. Although some debate occurred about which Gospels or Epistles should be included, all Christians eventually accepted all of the same 27 books in the same order. So, as long as you choose an edition that does not add explanatory notes opposed to a Catholic perspective, any reputable translation of the New Testament is fine.