Most dispensationalists understand that the doctrine contained in the book of Hebrews is indeed for those in the Body of Christ. They understand that the author of the book is telling those who received the book to leave Judaism.
Sir Robert Anderson wrote that "the distinctive sin with which the Epistle deals is unbelief, and unbelief that savours of apostasy, a going back to Judaism by those who had accepted Christ as the fulfillment of that divine religion...the Epistle to the Hebrews sought to teach him that as a partaker of a heavenly calling, he had to do with heavenly realities, of which the glories of his national cult were but types and shadows...nothing but the revelation of something higher and more glorious could ever wean him from his devotion to the national religion" (Anderson, Types in Hebrews, [Kregel Publications, 1978], p. 114,124).
Cornelius Stam, the founder of the Berean Bible Society, wrote that the author of Hebrews "exhorts them to leave, finally and fully, the religion of Judaism with its shadows, for Christianity, with its substance and reality" (Stam, The Epistle to the Hebrews, [Berean Literature Foundation, 1991], 69).
It seems like the only dispensationalists who actually believe that it is not doctrine for the Body of Christ make up a small minority, made up of the Bullingerites and what I call the Neo-MADs (those who have adopted Bullinger's teaching into their body of beliefs).
