RESPONSE: “Canon of Scripture" refers to the whole of inspired Scripture; the books that are accepted as inspired by God.
There are three classes of ancient texts relating to the Bible: protocanonical (first canon) books, which all ancient Christians agreed were inspired Scripture; deuterocanonical (second canon) books, which some Christians considered to be divinely inspired Scripture while others disagreed; and apocrypha, which all orthodox Christians agreed were not divinely inspired. The Old Testament deuterocanonical books are Tobit, Judith, Wisdom, Ecclesiasticus (Sirach), Baruch, 1 and 2 Maccabees, chapters 10-16 of Esther, and three sections of Daniel: Daniel 3:24-90, Daniel 13, and Daniel 14. The New Testament deuterocanonical books and passages are Hebrews, James, 2 Peter, 2 and 3 John, Jude, Apocalypse, Mark 16:19-20, Luke 22:43-44, John 5:4, and John 8:1-11. There are numerous apocryphal books which no Christians believe to be part of Scripture, like the Gnostic scriptures collected in the Nag Hammadi Library.
The Catholic Church has long recognized all of the deuterocanonical books listed above as inspired Scripture, and that is why the Bible has 73 books (46 Old Testament, 27 New Testament). Protestants, beginning with Martin Luther, rejected the Old Testament deuterocanon in the 1500s, and that is why their Bibles have only 66 books, plus shorter versions of Esther and Daniel. The Eastern Orthodox accept the 73 books Catholics accept, plus Psalm 151, 3 and 4 Maccabees, a book of Esdras, and the Prayer of Manasseh.
DISCUSSION: The earliest Christians did not have a dogmatically defined canon of Scripture. However, there is solid evidence that the Septuagint was used and accepted by the Apostles and their successors. Translated around 250 B.C., the Septuagint followed the Alexandrian canon and therefore had seven more books than the Palestinian canon. Because of the numerical difference, some Christian theologians disagreed over which books should be considered inspired by God.
After the destruction of the Temple in 70 A.D., some Hebrew scholars in the Palestinian Jewish community began to question the books in the longer canon. As a result, some Christian scholars also debated the acceptance of these books as divinely inspired. As the debate developed, two classes of Old Testament books were distinguished: the homologoumenoi, that is, the “accepted" books, and the antilegomenoi or amphiballomenoi, that is, the “contested" books.
Ultimately, Christians accepted the following deuterocanonical books as divinely inspired: Tobit, Judith, Wisdom, Ecclesiasticus (Sirach), Baruch, 1 and 2 Maccabees, chapters 10-16 of Esther (labeled chapters A-F in modern Catholic translations), Daniel 3:24-90 (Song of the Three Young Men), Daniel 13 (the story of Susannah), and Daniel 14 (Bel and the Dragon). When Latin replaced Greek as the common language of the West, the term protocanonical replaced homologoumenoi. Likewise, deuterocanonical replaced antilegomenoi. The term apocrypha referred to books which were clearly not inspired Scripture. It did not refer to the deuterocanon.
The New Testament, like the Old Testament, had its share of disputed books. Dozens of books and letters were being sent from church to church. Until the late 4th century, there was no clear ruling on which were divinely inspired Scripture, which were simply sound teachings, and which were neither. Most of the New Testament deuterocanonical books were contested because their apostolic authorship was uncertain. For example, it was not clear to all early Christians that Hebrews was written by an Apostle or an Apostle’s disciple. The passages in Mark, Luke and John were disputed because they did not appear in all manuscript versions of those Gospels. The usefulness of the New Testament apocrypha varied widely. Some apocryphal books, such as The Shepherd of Hermas and The Didache (The Teaching of the Twelve Apostles) were orthodox theological works which simply weren’t inspired. Other books, like the Gospel of Thomas and the Acts of Pilate, had passages which contained serious theological error.
Ultimately, Christians accepted the New Testament deuterocanonical books as divinely inspired Scripture. These books are Hebrews, James, 2 Peter, 2 and 3 John, Jude, Apocalypse, Mark 16:19-20 (the Ascension), Luke 22:43-44 (Christ sweating blood and the strengthening angel), John 5:4 (an angel stirred the pool), and John 8:1-11 (the story of the adulterous woman).
Precisely because of the various traditions and opinions on this matter, the Supreme Authority in the Church defined what belonged to the Canon of Sacred Scripture. Regarding both the Old and New Testament Canons, Pope Damasus I convoked a synod in 382 and defined the Canon of Sacred Scripture as we know it today. Pope Innocent I (401-417) sent this identical Canon to a Gallican bishop who had inquired about the matter. The Synod of Hippo (393) and the three Synods of Carthage (393, 397, 419) all confirmed the inclusion of the deuterocanonicals in the Canon of Sacred Scripture. By the end of the seventh century, the Oriental Churches had accepted the decisions of Western authority on this matter. In accord with the Council of Florence, Pope Eugenius IV issued the “Decretum pro Jacobitis" (Decree for the Jacobites) which listed the Canon of Sacred Scripture as including the deuterocanonicals. When the Protestants raised dispute over the Canon of Sacred Scripture, the Council of Trent made clear that no Catholic could question the divine inspiration of the disputed books.
Continued disputes over the Canon of Sacred Scripture center on disputes over authority in the Church. When the Oriental Churches broke with Rome, they denied the once accepted authority defining the Sacred Canon. However, they maintained that traditional use allowed acceptance of the deuterocanonicals, but such acceptance was not infallible. By the eighteenth century, they had established a Canon that included not only the deuterocanonicals but also some of the apocrypha. During the Protestant Reformation, Luther and the other reformists denied many of the Traditions and teachings of the Church. Their disputes over the deuterocanonicals allowed them to rationalize their denials of the faith by claiming a lack of support from Sacred Scripture.
Martin Luther and the other Reformists discarded the Old Testament deuterocanon because it contradicted sola fide (faith alone) theology. Luther also attacked some of the New Testament deuterocanon. He threatened to “throw Jimmy [the epistle of James] into the fire" and had serious reservations about the Apocalypse. After much dispute with the other Reformists, during which Luther denied the apostolic authorship and evangelical value of James, he ultimately retained the whole New Testament Canon. Nevertheless, he still called James an “epistle of straw." In order to disparage their accepted inspired status, he and his followers began referring to the Old Testament deuterocanon as “the apocrypha." Even though Luther did not consider the Old Testament deuterocanonical books as divinely inspired, he did not remove them from his translation of Scripture. Instead, he placed them in an appendix between the Old Testament and the New Testament. Until 1827, most Protestant translators continued to place these Old Testament books in the appendix position. At that time, the British and Foreign Bible Society removed them from their editions for the first time.
Thus, the version of Holy Scripture used by Protestants today is not only incomplete when compared to the version used by the Catholic Church, it is incomplete when compared to 300 years of common Protestant usage. Protestants today are using a Bible that has only been in existence for roughly 150 years, a manmade, not God-ordained, tradition.