Development of the New Testament canon writers. (Books not attributed to these three are: Matthew, Mark, Luke, Acts, James, and Jude. The authorship of Hebrews has long been disputed.) Many modern Protestants point to four "Criteria for Canonicity" to justify the books that have been included in the Old and New Testament, which are judged to have satisfied the following: The basic factor for recognizing a book's canonicity for the New Testament was divine inspiration, and the chief test for this was apostolicity. The term "apostolic" as used for the test of canonicity does not necessarily mean apostolic authorship or derivation, but rather "apostolic authority". "Apostolic
New Testament the Anchor Bible Dictionary), may be the earliest known New Testament canon attributed to mainstream Christianity. It is similar, but not identical, to the modern New Testament canon. The oldest clear endorsement of Matthew, Mark, Luke, and John being the only legitimate gospels was written "circa" 180 AD. A four gospel canon (the "Tetramorph") was asserted by Irenaeus, who refers to it directly in his polemic "Against the Heresies", "It is not possible that the gospels can be either more or fewer in number than they are. For, since there are four zones of the world in which we live,