It is ironic that Protestants reject the inclusion of the deuterocanonicals at councils such as Hippo (393) and Carthage (397), because these are the very same early Church councils that Protestants appeal to for the canon of the New Testament. Prior to the councils of the late 300s, there was a wide range of disagreement over exactly what books belonged in the New Testament. Certain books, such as the gospels, acts, and most of the epistles of Paul had long been agreed upon. However a number of the books of the New Testament, most notably Hebrews, James, 2 Peter, 2 & 3 John, and Revelation remained hotly disputed until the canon was settled. They are, in effect, “New Testament deuterocanonicals.”
While Protestants are willing to accept the testimony of Hippo and Carthage (the councils they most commonly cite) for the canonicity of the New Testament deuterocanonicals, they are unwilling to accept the testimony of Hippo and Carthage for the canonicity of the Old Testament deuterocanonicals. Ironic indeed!
James Akin, “Defending the Deuterocanonicals.” The Nazareth Resource Library, 1996.