There isn't a "book" in the Bible, NT or OT, which, says, "OK, folks, here's the list of the official books!" The index is added later, of course.
Funniest conversation I ever had with a fundamentalist ended up with him saying everything in the Bible was to be taken literally EXCEPT when Jesus says, "This is my body" at the Last Supper. "That's just symbolic," he said. Along with the eating and drinking part, etc. Contrary to some posters here and elsewhere, I don't think that a person has to understand every word of the ancient Hebrew and Greek scriptures to be a valid Christian. That's an impossibility anyway. Most interesting book on sacred scripture I have seen is Henri de Lubac's book on Medieval Exegesis.
As for the earlier nonsensically absurd bugaboo about "theology" being banned by the Bible or something, there are some who seem not to have a clue and apparently refuse to read the ABCs of Christian history. All that really means (Grk:theos, God, logos, study) is "the study of" God, religion, sacred texts, religious teachings, etc. Any scholarly or intellectual discussion about the meaning of divine revelation and the drama of salvation - which, of course, is what everyone has been doing (more or less, less in some cases) on this thread. There is a wide and broad tent for critical and theoretical discussions of religion and affairs of the spirit within the Christian community.