Good point. I thought that’s what you were getting at in your OP also.
Imagine for a moment you’re this Hebrew guy (Barat, not Bonnie) living around 20 A.D. (pre-Easter) that loves God with all your heart and more importantly God loves you. You know each week that you are a sinner in need of God’s forgiveness each week, month, year. You need His grace and mercy (Heb 4:16) and forgiveness for your sins. You have throat cancer, so to speak, on a weekly basis. But you’ve literally never heard of Jesus Christ before because He’s not started his minister or fulfilled the Old Covenant just yet. So, you do what any good Hebrew does. You do what God’s told you to do up until Christ Jesus becomes your High Priest. You sacrifice regularly as required, follow all the Laws of Moses as required, support the various High Priests serving during that time as required, etc. etc. And you know what, it works! God imparts His Mercy, Grace and Forgiveness to you for those Old Covenant sacrifices. (they aren’t old just yet, remember this is pre-Easter). But over and over again, in just a week’s time (or less) you find yourself feeling that need for forgiveness yet again and again. Over and over. The cancer is back. So, you re-sacrifice yet again and again. And on and on it goes. Sin-Sacrifice-Forgiveness, Sin-Sacrifice-Forgiveness, … Why? Because you are still so weak, so sinful and obligated to do your routines (see Heb 5:3). The Holy Spirit is not sharing your life with you, just yet. And it works again and again. Remember, this is pre-Easter. I imagine that cyclic feeling to be about like having throat cancer that took your voice away but then you get cured and your voice back. Yet this all occurs on a weekly/monthly basis. Over and over again.
If you are like me, this is kind of a foreign idea (living like a pre-Easter Hebrew). It’s hard to imagine me sacrificing animals for the forgiveness of my sins, but important to the proper interpretation of this text, to do so, IMO.
I’ve never sacrificed an animal before. Never even thought about actually doing it, frankly. But they did and received the benefits of it each time they did. Obviously if done sincerely, though. My point is, put yourself in a Hebrew’s situation back then (1st Century) for a moment and think about Heb 4, 6 and 10
from their perspective for a moment. It’s called the book of Hebrews for a reason!
Then along comes Jesus Christ, your Messiah, His Passion and Easter. You are
enlightened (Heb 6:4) about this new High Priest (Jesus, Heb 5:10) who has just recently become your new source of forgiveness, Mercy and Grace and better yet-Eternal Salvation (Heb 5:9). You truly come to realize that He is the fulfillment of all the Old Law you’ve been following your whole life up until this point. No more scarifying over and over again to obtain God’s Mercy, forgiveness and Grace. The author of Hebrews calls that way of receiving forgiveness “dead works”, Heb 6:1, 9:14 now that you’ve been enlightened to the New Way. You have Christ now as your High Priest and you have Eternal Salvation and complete sin forgiveness as a result. The old ways of forgiveness is done away with, but they are still fresh on your mind, so to speak. But now (having Christ) you are permanently cured of that dreaded cancer. It would be “impossible” to want to go back to that old cycle of having cancer, getting cured, having it again, getting cured again, etc.
For the life of me, I’ve never understood way people think Heb 6:4-6 is an anti-OSAS passage at all. It’s actually quite clear that it’s an OSAS encouragement, not anti-OSAS proof text. For goodness sake, just read v9 or v15, and v19, etc. The whole chapter (and the ones before it an after it) is about God’s giving a newly converted Hebrew believer; “
powerful encouragement”, that’s “
like an anchor of the soul”, “
steadfast and firm”.
But more directly to the OP, He says what is
impossible in these verses (A Hebrew turned Christian going back to the old covenant), not what’s possible (de-salvation). What could be more OSAS?
Heb 6:4-6 (LEB) 4 For it is impossible concerning those who have once been enlightened, and have tasted the heavenly gift, and become sharers of the Holy Spirit, 5 and have tasted the good word of God and the powers of the coming age, 6 and having fallen away, to renew them again to repentance, because they have crucified again for themselves the Son of God and held him up to contempt.
To turn a passage that tells us so clearing what’s
impossible (re-crucify Christ is impossible) into what’s possible (it’s possible to become de-saved) seems fundamentally inappropriate to this passage. Not to mention that nowhere in this text does it say anything about losing salvation. People mis-interpret (in my opinion) “
having fallen away” into ‘de-salvation’ or something like that, I guess. It’s odd really and shows just what a lack of clear anti-OSAS teaching there is in the rest of the Bible to resort to pointing to “
having fallen away” as somehow meaning loss of salvation.
If you want to know what the author means by “
having fallen away”, just read the context. Don’t insert your own context into it, Is my belief. If the author of Hebrews had meant “loss of salvation”, he could have easily said so. I don't see where he did mean that at all.
The context of the whole discussion (from chapters prior and after 6:4-6) is about a recent 1st Century Hebrew convert to Christianity (which none of us are anyway). I assume none of us have ever sacrificed animals IAW the Old Law. This particular passage is about potentially turning back (falling away from the new to the old, to the Old Covenant ways of repeated sacrifices,
dead works as he calls it in v1) in my opinion. Which he says is impossible to do. Just as impossible as it is to crucify Christ again. It's called a ‘reductio ad absurdum’ (it’s Latin, I think
reducing another's argument to the absurd by taking their premise(s) to their logical conclusion). Paul uses this form of logical argumentation often throughout his letters. (see 1 Cor 15:11-17) for example.
His point is that a Hebrew who’s turned Christian, i.e. “been enlightened and shares the Holy Spirit (by that I mean one that truly loves the Lord and the Lord loves him, for goodness sake he “shares the Holy Spirit”) can no more turn back to the Old Covenant ways (
repentance from dead works, see v1) anymore than you can re-crucify Christ. It’s absurd and thus
impossible.
It's most definitely not a passage about a 21st Century Christian turning from back from Christianity into Atheism. Which is how the anti-OSAS person presents it so often.