Jim,
There are many similarities between this passage and that in chapter 10, which we will see as we progress though the details of the passage, as we did in chapter 10.
Heb 6:4It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit,
5who have tasted the goodness of the word of God and the powers of the coming age
6and who have fallen away, to be brought back to repentance. To their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.
7Land that drinks in the rain often falling on it and that produces a crop useful to those for whom it is farmed receives the blessing of God.
8But land that produces thorns and thistles is worthless and is in danger of being cursed. In the end it will be burned.
The first similarity is the description of the spiritual experience of those to whom he is writing. The chapter opens in this manner:
"Therefore let us move beyond the elementary teachings about Christ and be taken forward to maturity, not laying again the foundation of repentance from acts that lead to death, and of faith in God, instruction about cleansing rites, the laying on of hands, the resurrection of the dead, and eternal judgment." (Heb 6:1-2) The ones to whom the message of chapter 6 (and following, especially including chapter 10) are actually true believers, if yet still weak babes (5:11-ff), because they are going to be talking about going on to maturity. The focus is not on the "tares" but the wheat, and the language will prove it.
Heb 6:4 begins with the describing of one who has been enlighten, Greek photizo, which means, "to imbue with saving knowledge" (Thayer) Now this could be construed as just being exposed to the information about salvation, but that would not be either proper biblical usage or proper English. It is not enlightenment about how to be saved, it is enlightenment that saves. This would be especially true of those whose soteriological stance tends to the Calvinistic side of the equation, because knowledge that saves, is not knowledge that can be comprehended unless one is regenerated or born again; it is spiritual understanding that unspiritual minds cannot understand. (1 Cor 2:12). But, as is usually the case, the best evidence is the evidence within the text itself, and the next descriptor strengthens my case beyond any reasonable doubt.
Not only are they enlightened, they have "...tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the word of God and the powers of the coming age... "(Heb 6:4-5) "Tasted", Greek geuomai, when used figuratively, always means to experience the reality of something, such as when Jesus spoke of some not tasting death before the coming of Christ's Kingdom. (Matt 16:28) Thus, the tasting of the heavenly gift (salvation/eternal life), and thus, being those have shared in the Holy Spirit, which have tasted the goodness of the word of God, and the power of the coming age (again a reference to the Holy Spirit working within the believer) are all experiential in fact. This is not true of "tares"! This can only be a person who has really been saved!
Next, the author shifts to a contrasting reality statement by saying that those who have experienced these things in the past, but now "have fallen away" will find renewal to their former state of repentance, an impossibility! One thing is obvious: You cannot fall from something that you haven't attained! You cannot fall from a tree or a wall or a mountain cliff you haven't climbed. You cannot leave something you've never reached! There is no middle ground between being forgiven or being unforgiven; you're one of the other. Likewise, you cannot be renewed to repentance unless you were once repentant. You cannot fall away from a faith that you never possessed!
The fallacy I find in your interpretation is that you equate the experience level of the wheat and tares until it comes to the point of falling away, then it can only be tares! This is blatant eisegesis for there is zero evidence of non-Christian tares being in the author's mind. It doesn't say that tares and not wheat can fall, in fact it says nothing at all about the differential between wheat and tares, and yet this is precisely what you are making an implicit necessity to your arguments. If the experience of the tastings are equal for both groups (wheat and tares), then they are in equal standing before God. You can't have it both ways; if they are equal in there experiential qualities, there can be no inequity in their potential falling away.
Heb 10:9 Even though we speak like this, dear friends, we are convinced of better things in your case—the things that have to do with salvation.
10God is not unjust; he will not forget your work and the love you have shown him as you have helped his people and continue to help them.
11We want each of you to show this same diligence to the very end, so that what you hope for may be fully realized.
12We do not want you to become lazy, but to imitate those who through faith and patience inherit what has been promised.
Here again, we have a strong similarity with the way he makes his arguments in chapter 10. The author turns to encouraging and showing personal confidence that the hearers will stay true to their faith but he says something interesting here, that the things he is talking about are "the things that have to do with salvation"; whether they are going to be saved or not and why! The author is confident because a) "God is not unjust;
he will not forget your work and the love you have shown him as you have helped his people and continue to help them" (vs10), and b) "We want each of you to show this same diligence to the very end,
so that what you hope for may be fully realized, (vs11), and finally, c) "We do not want you to become lazy, but to
imitate those who through faith and patience inherit what has been promised." (vs12)
You will note, that the inheritance that "has been promised", and the full realization for "what you hope" is contingent on their "show[ing] this same diligence to the very end", and that God will do "what is promised" for "those who through faith and patience " come to actually "inherit" said promises. In other words, there is no guarantee of "showing this same diligence to the very end", but only that God is faithful to do what he promises for those who do.
So I have now taken deliberate pains in showing the context, lexigraphical, and consistency of thought for all three of my texts in support of my original post on this thread (which strangely enough has been, to my knowledge at this moment, ignored by the original author of the thread...hmmm). I think it is a far cry from your wheat/tares theory, which, in my humble opinion and experience, cannot stand to the actual evidence of the texts themselves.
Doug