"If you are a believer". There's the rub ---
do we have a choice to be a "believer"? Overwhelmingly, yes. From start to finish.
Tell me something --- when Paul (he wrote Hebrews) says
"SHALL we not much rather BE subject to the Father of spirits, and live?" --- was he conveying a choice? And can "live" mean something
other than "eternally"?
You are correct. "Undisciplined", is "unbelieving"; there is not one without the other. So too "submitting to God's discipline",
and "believing".
If you are without discipline (of which all have become partakers), then you are illegitimate and not sons. We had earthly fathers to discipline us, and we respected them; SHALL we not much rather BE subject to the (discipline of the) Father of spirits, and live?" Tell me how that's
not conveying a "choice to receive His discipline (and live eternally), or to REFUSE His discipline
and not be His sons but be illegitimate."
How is it not? What if you don't?
If one can "turn away from God", then there's
only wrath for him.
Surely you accept that there is no
turned-away-from-God-SAVED" position...
You did not answer Heb2:1-3; what's your answer? How do you understand it?
Then tell me how you understand verse 9?
You said
"how shall we escape if we turn away from Him-who-warns-from-Heaven", means "we cannot turn away from His discipline". How does it mean that?
Teach me; tell me how you perceive verses 8-9.
If one
refuses to learn from discipline, then how is that discipline
"not refused"?
Do you believe there is such a thing as an "undisciplined believer"?

Where is "repentance" in that?
Then just help me to understand what verses 8-9 are saying to you; and if you perceive there is such a thing as a "not-learned-from-discipline-BELIEVER"
Afraid?
"There is no fear in love, perfect love casts out fear; he who fears is not perfected in love." 1Jn4:18
"I know whom I have believed, and am convinced that He is able to guard what I have entrusted to Him.
Now --- guard, by the Holy Spirit that indwells us, the treasure entrusted to you." 2Tim1:14-16Then how do you explain Col2:6-8?
"As you have received Christ, so walk IN Him, having firmly been rooted and now being built up in Him and established in your faith, jmust as you were instructed and overflowing with grattitude. SEE that no one takes you captive through philosophy and empty deception, according to the traditions of men, according to the elementary principles of the world, rather than according to Christ."
Tell me, Sawdust --- what is Paul saying?
That "we walk BECAUSE we cannot be lost"?
Or "walk SO THAT you're not lost"?
It can't be "both"; an obligation
is something we SHOULD do, not something we
cannot avoid. Please tell me
what kind of walk will "lose you Christ's posessions"?
What is it that removes "heavenly rewards", but not "salvation itself"? What do you have to do to lose some? (Really hope you ansswer this...)
It's up to you to show me how.
He doesn't say that
anyone won't escape discipline. He says "SHALL we not much rather BE subject to the (discipline of the) Father of spirits, AND LIVE?"
Being subject to His discipline, is fully a choice. You're right,
those WHO believe, WILL be subject; but if "undiscipline" is a choice,
then unbelief is the same choice.
In Heb4:11, just after speaking of how the Israelites failed to enter the Promised land
because of disobedience/unbelief, he says:
"See that you don't FALL and fail to enter God's rest by IMITATING their unbelief and disobedience."
Did the Israelites
refuse God's discipline? Yes.
Are we warned not to IMITATE their refusal?
YES!
Tell me how I'm mis-interpreting it.