Hebrews is great for apologetic questions! In the first part of chapter 7 the question was: Jesus can't be who you say he is because he isn't a priest from the line of Levi. Therefore he can't sacrifice, therefore he can't save. See the previous Hebrews post to see how the writer kicks that into the long grass.

From v11 the implicit question being asked changes. Not now that Jesus can't be who we say he is, but that he is simply not necessary. It seems that people were arguing that acceptance with God (perfection in the language of the letter) was obtained through the Law of Moses and the Levitical priesthood and therefore Jesus is simply superfluous. "We have everything we need regarding God already, we don't need anything else" seems to be the issue.

This raises a BIG question for Christians - namely what is our relationship with the Old Covenant Law of Moses. Does it provide everything we need for a relationship with God? If not, does Jesus fulfil it, replace it, tear it up, or what? That is what the writer sets out to answer. The answer will determine how we think we please God, how we can be holy and whether we need human priests among other things. It is a subject for way more than a blog post, but if you want my fuller answer get hold of a copy of my book Finding Joy.

This is how the argument goes:

Q. Was the levitical preisthood, and the Law that depended on it (note that law depends on preisthood not the other way around in 7:11) enough to make people acceptable to God.

A. No, for at least three reasons:

It didn't make people perfect, which is the necessary standard v11. And neither did the Mosaic Law in v19
The priests weren't blameless (v27) in that they were weakened fatally in their task by their own sin (v28)
They couldn't do anything lasting because they eventually died. Therefore no priest could guarantee any permanent relationship with God because that depends on having someone eternally interceding for us (v25)

Note this well: the Old Covenant, glorious though the Law of Moses was, is inadequate for our relationship with God. Read Romans 6 and 7 and Galatians 3 if you want a more thorough treatment of why.

Jesus Christ, on the other hand, was holy, blameless, pure, set apart and exalted v26. He has been perfected for ever v28 (ie declared to be acceptable to God). He intercedes indefinitely and therefore saves completely and eternally (v25). He is not an Earth-bound priest, but a priest in Heaven whose work is completed 8:1-2. So the hope offered through God's promise in Jesus is better that that of the Old Covenant priesthood and Law.

What then the old regulation? The writer is clear that it is now set aside as the means for being acceptable to God. It does not help us draw near God (v18-19). It is by the better hope that we draw near. More than that it has been declared obsolete (8:13).

Time for one application: don`t trust Old Covenant religion to get you anywhere with God. Don`t trust anyone who tells you that you need a mediator apart from Jesus. That is Old Covenant priesthood and it is inadequate. Don`t trust anyone who tells you that pleasing God consists in obeying the Law of Moses or that the Law of Moses is the required standard for holiness that you have to attain. Hebrews is quite clear that we need Jesus precisely because that is impossible. If we go back to trying the impossible then we are saying that we can do it and we no longer need Jesus. Exactly what the writer was refuting.

He has done it all. This is an argument to not trust works, not trust religion and not trust human priesthood. Only Jesus. He is not superfluous, he is entirely essential and utterly sufficient.