(I hope this makes sense)
Let’s say that in the era of early Christianity there was a rich man who had heard rumors of a teacher called Jesus and was curious about him. He enjoys reading very much so he sent a servant to find some writings attributed to him or about him.
The servant is sent to the library of a friend of his master. The owner of the library is a non-religious pagan who is a collector of works of all sorts. When he learns that his friend wants some books relating to this Jesus fellow he says he will happily lend a few books to his friend.
He brings the servant to a room and against a wall is a shelf filled with works. The man says "Here is my collection of writings which are scripture pertaining to this Jesus fellow"
The servant knows that he can not bring all the scrolls so he asks the man which ones he should bring.
“Well” he says, “I have a rather large collection and haven’t really read much of them. I can tell you this row is filled with works called Gospels, perhaps you should bring some of these first. They’re named after their author. This one is Matthew, this one is Mark, this one is Peter, this one is Mary, these two are Thomas, this one is Luke, this one is Judas, this one is John, this is Marcion and this is Mani. I also have some other books relating to Jesus, this one is called the Apocalypse of John of Patmos, this is the Apocalypse of Peter and copies of letters written by men such as Paul of Tarsus, James of Jerusalem, Marcion of Sinope and many others”
Now for a second let’s just remember to put on some suspension of belief and ignore any anachronisms present. How would the servant or his master or the master’s friend be able to differentiate between the apocryphal books and the canonical books? Suppose the friend of the master had such a huge collection that among the works he owns would be the books that make up the canonical Bible. In what way would they be able to tell the inspired texts from the uninspired or downright blasphemous?
Would they be able to what is canonical and what isn’t through divination of some sort? (If so I’d like to see scripture supporting this)
If the Bible was all that was needed for faith then the Bible is to be the source of all theology. What books make up the Bible is part of theology. Nowhere in the Bible does it tell you what books are to be a part of the Bible.