At the beginning of this essay we discussed the prevalent opinion of the late date of the Epistle [HEBREWS] and found reasons for traversing that opinion. The chief reason was the difficulty of accounting for the intensity of the Epistle in a later period, and the ease with which it could be explained if it were written when the Jewish revolt against Rome was beginning, to a small group of friends of like mind and education with the author, who were hesitating to break with their nation, and who felt themselves called in honour to forsake Christ, to adopt unchristian politics, and to take up arms for the old religion. We must of course remember that the author was not mainly engaged- though he was primarily- in talking about this war. It was important to him, for his friends' decision to hold aloof would be the immediate act of faith to which he was urging them.
from page 209, The Epistle of Priesthood