And to amplify what you said earlier, it is the basic credibility of other historical-theological works of man, supported only for the fact of the immediate quote made by the human author in its utility as a general principle that God can use by allusion to the outside author. So when "All Cretans are liars" or "we are his offspring" are quoted by the Bible, they are not quoted to support the full context of their authors, but to support the general principles and to give God's context for them. (God has Paul state that the testimony of Epimenides "is true" and not a paradox as we play that it is.) So Enoch is useful for historical context but not for independent doctrine.