When speaking to the average Christian and you ask them about the canon they may look at you and have a blank stare upon their face. Or you may get the general response of “the books of the Bible.” However, Carson and Moo in their An Introduction to the New Testament give us a very detailed response, it reads, “Etymologically, (kanōn, “canon) is a Semitic loanword that originally meant “reed” but came to mean “measuring reed” and hence “rule” or “standard” or “norm.” Depending upon which authors you read there may be three or four rules of canonization. What they all agree upon is that the work needed to be written directly or indirectly by an apostle, also the books orthodoxy (whether or not the book conformed to the churches “rule of faith”), and also its use in the early church. Kostenberger also points out that the books “antiquity” played a role in whether or not it was canonized.
Depending upon which scholar you read the NT could have taken fifty years or more to complete or as Paul Enns Believes “…the writing of the New Testament books probably encompassed less than fifty years….” There are some who would argue that the New Testament canon was compiled sometime in the fourth century and others believe in the second century. In all reality the canon was started when the first books were written and more than likely closed when John finished writing Revelation. I personally enjoy the way Kostenberger answers those who believe it was done at a later date, he says,
If this assessment is accurate, the idea of a NT canon was not the idea of some fourth-century Christians or even the product of a second-century reaction to the truncated canon of Marcion. Rather the concept of a New Testament flows organically from the establishment of a new covenant, predicted by the OT prophets and instituted in and through the Lord Jesus Christ himself, who thus became the very fount not only of all Christian salvation blessings but also of the NT Canon.
Early Christians felt the need to create a canon, because there were some who were attempting to call certain writings as authoritative that were not. Then there were men like Marcion who decided that they did not like certain text and felt they lacked validity so he wanted to pick an choose what books made the cut. So it would be at the council of Carthage in 397 where it was agreed upon that no books should be read as divine Scripture except those agreed upon (which were the twenty-seven books we now have.)
In my opinion the apostolicity of a book is what makes it most valuable to scripture. I say this because if it were written by an apostle or someone close to them, you should be able to trust that the words they speak and the life they live are different because of the gospel. While the one thing that has the least amount of weight for me is how the material was used in the churches. The reason being that the churches were scattered across many different countries and it would take time for things to reach a destination, and there were some places that argued about who they followed. If someone were to argue with me that the canon should still be open the best answer I could give is in line with Kostenberger, “… the sovereignty of God in the production should be recognized. If he did not see fit to provide the letter for 2,000 years of Christian history, why would anyone suppose that a new letter should be added to the canon of Scripture now?”
According to our textbook, “The traditional evangelical view affirms God’s activity in the formation of the canon.” Some of the most recent developments in scholarship on the NT canon include men like Sundberg, who have called for a “revised history of the NT canon.” “According to these writers, at this early stage of the canonical process, a particle work could have been viewed as “Scripture” (i.e., a piece of sacred writing) but not as “canonical” because this kind of canonical consciousness and sense of a “closed collection” of NT books only emerged in the third and fourth centuries.” The problem with that thought is that Sundberg and his contemporaries have tried to force a different time upon the Muratorian canon which is believed to have been written in the second-century. It has also been pointed out that just because the term canon did not come in to play until the late third to mid fourth century, does not mean that there was a possibility another set of terms could have been used to communicate what was later known as the canon.
According to Sundberg and others “…the notion of a closed OT canon in the first two centuries, maintaining that the OT canon was not completed until at least the fourth century and that the early church received the OT canon before Judaism determined the canonical boundaries of the Hebrew Scriptures. According to these scholars, the collection of Scripture was a fluid process.” Elwell, makes a great argument against this because, “By the time of Jesus the OT, called Tanaach by modern Judaism, consisted of the Law, Prophets, and Writings (Luke 24:44). Opinions about the full extent of the canon seem not to have been finalized until sometime after the first century A.D.”
There were several books that were slow to be received into the canon of Scripture inside of the Roman Empire in the west there were the books of Hebrews, James, 2Peter, 3John and Jude. To the East the list looks almost exactly identical except instead of Hebrews they included Revelation. The book that surprised me the most to show up on these lists would have to be the book of James. It meets the criterion mentioned before, it was written by the brother of Jesus Christ, it is believed to have been written before most of Paul’s writings, as you read through it you can feel the orthodoxy coming off of it (especially chapters 1-2). This book has been called by some the proverbs of the NT. So by it being so rich in wisdom and meeting the other criteria it is hard to understand why it was so slow to be received.
 D. A.Carson, and Douglas J Moo.( An Introduction to the New Testament. Grand Rapids,, MI: Zondervan, 2005)726.
Andreas J. Kostenberger, L. Scott Kellum, Charles L. Quarles. (The Craddle, The Cross, and the Crown. Nashville: B&H Publishing Group, 2009)9-10.
 Paul Enns, (The Moody Handbook of Theology. Chicago: Moody Publishers, 2008)25.
 Kostenberger, The Cradle, 30.
 Water A.Elwell, ed. (Evangelical Dictionary of Theology. Grand Rapids,MI: BakerAcademic, 2001)156.
 Kostenberger, The Cradle, 29.
 Ibid, 4.
 Ibid, 13.
 Elwell, Evangelical, 155.