More on Covenant/Election in Hebrews

Q: Does Hebrews distinguish types of covenant membership?

I think it does:

• You can be a son or an illegitimate child (12:8).
• You can fall away from the living God (3:12)
• You can be the sort of land that drinks in the rain but produces thorns and thistles (6:8)
• You can drift from what you've heard (2:2)
• You can be Esau and sell your birthright (12:16).
• It’s possible to leave Egypt but fail to enter the land (Chapters 3-4).
• You can be enlightened, taste the heavenly gift, share in the Spirit, taste the goodness of the word and the powers of the age to come, and yet fall away irrevocably (6:4-6)
• You can shrink back and be destroyed (10:39)
  
• You can have come to Zion but refuse to listen to the one who speaks from heaven (12:25).
• You can show contempt for the blood of the covenant that sanctified you (10:28-29).

• And yet, it's only if we endure that we are his house/ partakers of Christ (3:6, 14).

Q: But isn't some of this 'you're in the covenant' language hypothetical?

Well, take a particular example - one of the warning passages in Hebrews.

Heb. 10:28-29: Anyone who has set aside the law of Moses dies without mercy on the evidence of two or three witnesses. How much worse punishment, do you think, will be deserved by the one who has spurned the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace?

I must admit to finding this passage still fairly difficult, (especially since I'm convinced of limited atonement, which closes down the options for interpreting this verse). But, the trouble with ‘sanctified’ being hypothetical is that wouldn’t that mean everything else is hypothetical too? So the passage would be saying something like this:

"The bad news for apostates is that they profane [but they don’t really profane] the blood of the covenant [which covenant they were never a part of] by which they were sanctified [though they were never actually sanctified by it]. Man, someone who has done [i.e. not really done] any of that will face a far worse punishment than the Israelite under the old covenant who disobeyed the law [which they actually were obliged to obey as part of the old covenant, because the old covenant did have members who were not decretally elect to eternal salvation, unlike the new covenant]."

In short, the new covenant brings worse punishments for non-members who disobey its terms than the old did for those who really were members and disobeyed. Which doesn't make sense to me.

It could be, of course, that the passage does not mean 'sanctification' in the exact same way that some other parts of the bible and some confessions of faith and various (important) theological discussions mean it. In that sense they were never sanctified, sure. But maybe that’s not the only thing signified by 'sanctified,' nor is it the only kind of sanctification the covenant has on offer.

Which means we're back to distinguishing (though not separating) covenant and election, and discussing types of covenant membership.