Who decided which books should be included and which excluded from the Bible(s)? Why are there differences in the Bibles for Catholics, Protestants, and Jews?
Here's the story of how the various versions of the Bible came to be, insofar as we've been able to piece it together.

The Pentateuch or Torah was accepted as Law very early--according to tradition, since the time of Moses, around 1250 BC. Most documentary scholars say bits and pieces were accepted as Law from early times, but that the books did not take final form until around 400 BC.

In 70 AD, as a result of continuing tension between the Jews and their Roman overlords, Jerusalem was besieged and destroyed along with the Temple. The destruction of the Temple in 70 AD was a turning point in Jewish history. It remade Judaism. Where before Jewish life revolved around the Temple, sacrifice, and the priests, it now became more fragmented, centering on local communities and prayer, led by rabbis. Fragmentation meant that there was no longer any central authority to which Jewish leaders could refer.

Around the time that Jerusalem was under siege, Rabbi Johannon ben Zakkai asked and received permission from the Romans to withdraw from Jerusalem and establish a place for Jewish study in a town near Jaffa that in Greek was called Jamnia (Jabneh in English, Yavneh in Hebrew--the current town of Yebna in Israel is built on the ruins). After Jerusalem fell, the academy became the center of Jewish learning. Scholars came there both to escape the destruction of Jerusalem and to debate how Judaism was to survive the loss of centrality. Naturally, a major point of discussion was what parts of Jewish literature were to be considered the word of God.

The Torah was accepted as the writings of Moses, and hence the basis of Jewish life. For the other books, the issue was primarily whether each agreed with Jewish law and history as found in the Torah. Each book had to be meticulously read and dissected and any anomalies resolved before it could be accepted as having the authority of Scripture. For some books, like Joshua, Judges, Kings, Isaiah, and Jeremiah, the discussion was brief. For other books, like Esther, Ecclesiastes, and the Song of Solomon, the discussion was lengthy.One inevitable result of such critical investigation of existing material was the establishment of an officially recognized text, even if there weren't one before.

Finally, around 90 AD, after much debate, 39 books were declared to comprise the Hebrew Bible, known to Christians as the "Old Testament." To Jews, of course, it's just the Bible. In one of the greatest successes of Jewish tradition, the list of canonical books has remained constant to this day. There are three large sections: Law (Torah or Pentateuch), Prophets (books telling the history of Israel, both histories and prophetic works) and Writings (psalms, proverbs, and wisdom literature).

The first part of the Christian Bible is called the Old Testament, and is largely the Hebrew Bible. However, knowledge of Hebrew was rare among the early Gentile Christians. Rather than attempt to create their own version of the Hebrew canon, they seem to have adopted what is called the Septuagint translation--a Greek translation of the Hebrew Bible plus some other books, dating from around 250 BC. The Septuagint apparently was the Greek version most commonly available (it was the basis for the earliest Latin translations as well). Manuscripts of the Septuagint include texts in Greek for which no Hebrew versions exist. These are now called the Apocrypha.

Origen was one of the very few early Christian scholars capable of working with Hebrew texts. He recognized that there were minor differences between the Septuagint text familiar to Christians and the Hebrew text used by Jews. He created the Hexapla, a massive "parallel columns" document comparing the Septuagint, other Greek translations, and the Hebrew versions.

Jerome, when he came to work on his translation (known as the Vulgate or "common tongue" translation), denied that any text other than the Hebrew canon was an authoritative basis for the Old Testament. But his view did not prevail.

The road to canonization of the New Testament was quite a bit rockier and quite the reverse of the Old. What ended in orthodoxy actually had its roots in heresy. While the Jews examined books to see if they were consistent with the main religious text (the Torah), the early Christians engaged in a more fundamental argument about what constituted Christianity and especially about the nature of Christ. Judaism was a centuries-old ancient religion with clear traditions. Christianity was new, had no tradition, and was torn with disagreement about what it was and what it should be.

The chief competitor to what would become mainstream Christianity was Gnosticism. The Gnostics believed that one did not need the intermediary of the church to experience God; that one could and should experience him firsthand if one knew the "secret tradition." One can easily see how this would threaten the orthodox church. But the Gnostics did give one important idea to the church. A second century Gnostic named Marcion gave us the first list of books he felt appropriate for a New Testament. It was very short, including only an edited Gospel of Luke and some of Paul's letters.
The first officially sanctioned canon of the New Testament was attempted by Irenaeus of Lyon. Irenaeus saw the effect Gnosticism was having on Christianity and feared that the church was splintering into factions. Formalizing doctrinal authority seemed to be the answer. He felt there were two sources of authority: Scripture and the apostles. A work could be accepted as canonical if the early church fathers used it. He never really compiled a list of books, but he did establish the basis for subsequent determinations of orthodoxy.

The work of Irenaeus was solidified by Bishop Eusebius some 150 years later, early in the 4th century AD. Eusebius was a prolific church historian who gave us most of what we know of early church history. He also gave us the first surviving list of New Testament books that matches what we have today, putting them in thematic order as well. Relying on the tradition of the church, Eusebius created what was probably the first Christian Bible as we know it today.

In 367 AD, Athanasius, bishop of Alexandria under Constantine the Great, set forth what proved to be the final canon of New Testament books in a letter listing 27 works. In 382 AD, at a synod held at Rome under Pope Damasus, church leaders influenced by Jerome adopted this list. The list was affirmed in councils at Hippo in 393 and 419 AD under Augustine and was officially ratified at a council in Rome around 473 AD. However, that council added no books that had not already been included in most earlier lists, and excluded no books that had not already been excluded by most lists.
The Greek Orthodox Church did not finalize its canon until the tenth century (primarily in doubt was inclusion of the book of Revelation). The Syrian Church had an even more complicated debate, and today recognizes only 22 books in its New Testament (excluding 2 Peter, 2 and 3 John, Jude, and Revelation). The Copts and Ethiopians have a few additional books included in their New Testament.

At the time of the Reformation, one of the main struggles between reformers and conservatives centered on the question of authority. To the reformers, the authority that had for centuries been held by the Church more properly rested with the Bible.

Early Christians regarded several Jewish religious books as the Word of God even though they had been denied a place in the Jewish canon--Maccabees, for example. Since they were Old Testament books (pre-dating Jesus), part of the Christian canon but not part of the Jewish canon, the Edicts of Trent in 1546 called them the Second or Deutero canon.

When Martin Luther reviewed Scripture during his break from Catholicism, he judged the contents of the Bible in the light of his convictions. He found a number of books difficult to reconcile with what he understood of the Gospel--specifically, II Maccabees, Esther, James, Hebrews, and Revelation. As the Cambridge History of the Bible puts it, "The test was whether a book proclaimed Christ. 'That which does not preach Christ is not apostolic, though it be the work of Peter or Paul; and conversely, that which does teach Christ is apostolic even though it be written by Judas, Annas, Pilate, or Herod.'" Thus the differences between the Protestant and Catholic/Orthodox bibles.

Some English Protestants--specifically, the Presbyterians and Puritans--took matters a step further and rejected the Apocrypha. Article VI of the Anglican "Articles of Religion" says of the Apocrypha that "the Church doth read for example of life and instruction of manners, but yet doth not apply them to establish any doctrine." The Westminster Confession, on the other hand, says the Apocrypha shall be "of no authority in the Church of God, nor to be otherwise approved, or made use of, than any other human writings."

Consequently, Protestant bibles in English are most often printed without the Apocrypha. As a result, most Protestants in the U.S. are unfamiliar with the Apocrypha and consider it part of the Catholic Bible.

Written by The Straight Dope Staff Members Dex and Eutychus.