In “Why Aren’t The Books Of The Apocrypha In All Bibles” you covered nicely why some books were not included in the OT. What about the NT? gospel of Judas , gospel of the Hebrews, infancy gospels, etc/.
The New Testament had pretty much come together by 150AD but there continued to be discussion about a few books until about 400 AD. It was not officially canonized until the Council of Trent in the 1500?s. For inclusion in the New Testament, books under consideration had to meet three basic criteria.
1. Were the authors either eyewitnesses to the events they wrote about or at least directly taught about them by the Apostles?
2. Was each book’s teachings consistent with church practice and tradition?
3. Was each book already in general use by the church, and accepted as the Divine Word of God?
In both Old and New testaments, the books included had to be generally viewed as the work of divinely inspired writers who faithfully converted God’s Word into written form (2 Peter 1:20-21). The books you mentioned, along with others that were considered, failed to meet these criteria.