The book of Hebrews is quite challenging, claims commentary author Donald Guthrie, since there are many open questions about authorship, historical setting and audience. More than most New Testament books, Hebrews requires detailed explanations of the background allusions within it, which reference the priesthood of Christ being directly linked to the old Levitical order. Above all, Hebrews deals with the important question, How can we approach God? - Publisher.