Bible scholars Dr. Norm Geisler and Bill Nix gave the following reasons:
(Quoted
in Josh McDowell, Evidence That Demands a Verdict, Vol. I (San
Bernardino, CA: Here's Life, 1972), pp. 35-36.)
1. Philo, Alexandrian Jewish philosopher (20 B.C. - A.D. 40), quoted the Old Testament prolifically and even recognized the threefold division [Writings, Law, Prophets], but he never quoted from the Apocrypha as inspired.
2. Josephus (A.D. 30-100), Jewish historian, explicitly excludes the Apocrypha, numbering the books of the Old Testament as 22 [Using the Jewish manner of accounting the O.T.]. Neither does he quote these books as Scripture.
3. Jesus and the New Testament writers never once quote the Apocrypha although there are hundreds of quotes and references to almost all the canonical books of the Old Testament.
4. The Jewish scholars of Jamnia (A.D. 90) did not recognize the Apocrypha.
5. No canon or council of the Christian church for the first four centuries recognized the Apocrypha as inspired.
6. Many of the great Fathers of the early church spoke out against the Apocrypha, for example, Origen, Cyril of Jerusalem, Athanasius.
7. Jerome (340-420), the great scholar and translator of the Vulgate, rejected the Apocrypha as part of the canon. He disputed across the Mediterranean with Augustine on this point. He at first refused even to translate the Apocryphal books into Latin, but later he made a hurried translation of a few of them. After his death, and literally "over his dead body," the Apocryphal books were brought into his Latin Vulgate directly from the Old Latin Version.
8. Many Roman Catholic scholars through the Reformation period rejected the Apocrypha.
9. Luther and the Reformers rejected the canonicity of the Apocrypha.
10. Not until A.D. 1546, in a polemical action at the Counter Reformation Council of Trent, did the Apocryphal books receive full canonical status by the Roman Catholic Church.