This epistle is not strictly in letter form. Actually a “word of exhortation,” it is a sermonic discourse recorded and sent as written communication. It was composed to move its addressees beyond the wall of protection afforded by Judaism and toward Christ who “suffered outside the city gate” (13:12). It attempts to redirect their gaze from a backward fixation on the provisional wilderness tabernacle to the enduring “city that is to come” (v. 14).
The key, therefore, to the epistle is its eschatological movement (Barrett, 366). It charts a course from former times through this final age to the promised everlasting inheritance, and it exhorts the reader to run this race with perseverance. It redirects the Jewish Christian from what is provisional and fading to what is enduring, from what is fragmentary to what is complete, from what is imperfect to what is perfect, from a sacrificial system based on separation and repeated mediation to direct access to the very throne of God once for all.
Older scholarship, citing parallels to Philo of Alexandria and the philosophical school that developed there, sees two levels of reality reflected in this epistle. The corrupt material existence of the present world order is contrasted with the perfect eternal world order. However, the contrast in Hebrews is not philosophical but historical. The movement is not from the temporal plane to the eternal plane, but from an age of incomplete revelation granted Moses to the age of perfect revelation in the Son (see Barrett, Hurst, Williamson).
The writer employs material from the OT to show divine sanction and purpose in moving beyond the pale of Judaism to Christ. The six major biblical passages cited by the writer point beyond themselves to something greater. In effect, they divinely argue their own self-obsolescence (Caird, 49). This proves God's age-long intention to replace the temporary tabernacle with an everlasting one, to replace the line of mortal high priests with One after the order of Melchizedek who has no beginning or end. The old covenant must give way to the new covenant; God has spoken.
In the fullness of time, through sufferings, Jesus pioneered the way into the presence of God. Access now has been gained to the very throne of grace. The course we are running has a finish line; faith has as its goal the promised entrance into God's own glory and Sabbath rest. To lay hold of such an inheritance, then to surrender it up again in the interest of self-preservation, is to trample the Son of God under foot and insult the Spirit of grace (10:29). Such shrinking back (v. 39) does not reflect the faith that will receive the better and lasting promise Christ offers (8:6; 11:39-40). This is reserved for those who “go to him outside the camp, bearing the disgrace he bore” (13:13).