Why are 14 books not in the bible?

Answer 1

There are a lot of books that aren't in the Bible, regardless of age or focus, but I presume you're referring specifically to the Apocrypha and/or the gnostic texts. For the latter, there are actually a few criteria that any book had to meet to be accepted into the New Testament canon:

Author: The author of the book in question had to have seen the risen Christ in person or, in the cases of Mark and Luke, been transcribing information given to them directly by someone who had. The gnostic texts in particular, for example, were largely written after that generation had died off and were attributed to apostles in their titles as an attempt to appear authentic.

Consistency: While each gospel is written from a different perspective, and therefore each has a different emphasis and slight differences in narrative format, they could not be accepted if they contradicted with each other.

Acceptance: This one is more a means of testing the others. The majority of the books in the New Testament had been distributed individually throughout the Roman Empire. Because of the way they were distributed, the books could be traced back to their source, which gives knowledge on when it was written and by whom. Newer books were not as widely accepted, and could be traced back to much more recent times and non-apostolic sources.

I feel like there were a couple others, but these three alone rule out most of the books that are raised in questions like this. As for the Apocrypha, they aren't actually New Testament, and therefore weren't considered when the canon was finally set down. The Jewish canon was closed later by the Jewish religious leaders. I don't actually know what criteria they used, hopefully another user of the site will come in and include that. Many of the apocryphal books are included in the Catholic bible, but not in others. Protestants believe that these books are, as Martin Luther described them, good for learning about the Jewish religion at the time of Christ and history between the Testaments, but not for gaining knowledge of or connection with God. Outside of the Roman Catholic church, they are largely not considered to have been inspired by God.