“What made them “holy’? Was it The Council of Laodicia in 311 A.D.?”
No... how could that make any kind of sense? The verse that was quoted was written long before that council was held. They were “holy” because they were the writings of the patriarchs and prophets of Israel, delivered to them by God.
“What about the estimated 3000 writings rejected ?”
That’s an extremely broad question. Some of those 3000 writings never would have even been considered by the council, because they were not Hebrew or Christian writings to begin with. When people talk about “3000 books”, they are including works from the gnostics and other pagan sects in order to inflate the total. The actual number of books that were under consideration was orders of magnitude smaller.
For those that were evaluated, they would have been evaluated individually, so the reasons for their not being included would have been individual reasons. You can’t give blanket answers as to why they were rejected, because they were rejected for reasons specific to each individual work.
How about the book of Batholomew? He was an actual eye witness and disciple. All the other books were written 50 to 110 year after the resurrection many by writers adopting pseudonyms. John may actually been John .Most are total hearsay accounts passed down for decades. Luke never knew Christ. Batholomew did know Christ and witnessed the post resurrection event. Why would this “holy “ scripture be left out. I’m just sayin.