I think it does bears mentioning that Blake, following Milton (in his Paradise Lost) felt it necessary to take the Bible itself as a model for writing his own visionary and epic poetry, although I think some will take issue with the "epic" description for Blake. But there's no question he considered himself writing on a level of importance equal to the Bible--at that time a very radical, even heretical stance. Has anything else of his entered into the popular canon to such an extent as Jersualem?