The Epistle to the Hebrews was written to encourage Jewish believers who had professed faith in Christ not to backslide from Him in order to return to the still impressive Temple rituals of pre–A.D. 70 Judaism.
Does the fact that the old covenant is the old covenant mean that the new covenant was “plan b”? The answer is no. God did not make a mistake with the old covenant. This article looks at the relation of the old covenant to the new covenant (the relationship between the Old Testament and the New Testament).