A worthy meditation
The chapter is overwhelming! You must read it today.
The contrast is not between one with infinite divine potential and one that has already reached that status. The divine window for us to look through in Isaiah 6 declares the difference between an unholy man and a Being, thundered by seraphim in an ecstatic, antiphonal trisagion to be “qadosh, qadosh, qadosh.” In heaven, believers of Jehovah will be forever separated from the presence of sin in their hearts, but they will always throughout eternity be eclipsed by the holy status reserved exclusively by the Hebrews for the God who is declared by the great Hebrew tetragrammaton, YHWH. God is holy in the absolute sense. Man is not (thank God for His altar so that my sins—past, present, and future—could be covered, atoned for). Man cannot evolve into Light, the defining essence of Theos. As a creature, man can only be “the light of the world” as he is a conduit or should I say, an earthen vessel for the Light of God. There is an infinite degree of difference between holy men and the God of burning holiness, transcendent holiness.
Unlike men of flesh and bones, God has never needed a purifying coal from the altar to be holy. Again, read it for yourself among the great words of Isaiah.
A significant question
Who all is included in the “us” of Isaiah 6:8? An OT hint to the Trinity. Or a host of angelic creatures, the full retinue of the King’s throne room. Or a council of gods surrounding YHWH.
A puzzling conclusion
In the last verse of the chapter (Isa. 6:13), David J. Ridges in Isaiah Made Easier (Springville: Cedar Fort, 2002) takes a stab at interpreting the KJV translation.
But yet in it (the land) shall be a tenth (remnant), and it (Israel) shall return (includes concept of repenting), and shall be eaten (pruned—as by animals eating the limbs, leaves and branches—i.e., the Lord “prunes” his vineyard, cuts out old apostates etc.; destroys old unrighteous generations so new may have a chance): as a teil (lime?) tree, and as an oak, whose substance (sap) is in them, when they cast their leaves (shed the old, non-functioning leaves and look dead in winter): so the holy seed shall be the substance thereof (Israel may look dead, but there is still life in it) (11).
BYU professor, Don Parry (whom we will see tonight), translates (similar to some of our modern translations) the same verse:
But yet [there will be] a tenth in it, and [they] will return, and will be for burning, as a terebinth and as an oak, which when felled, the stump is in it. The holy seed is its stump.
But in an endnote to this verse in Harmonizing Isaiah, Parry quotes, “Joseph Blenkinsopp, Isaiah 1-39: A New Translation with Introduction and Commentary (New York: Doubleday, 2000), points out that Isaiah 6:13 ‘is probably damaged beyond repair’ and that ‘attempts at reconstructive surgery . . . do not improve on MT, which is followed here in spite of the obscure terms’ ” (270).
But I would tell Joseph Blenkinsopp, “Don’t give up.”
Jesus in Idaho Falls 
I’ve made an attempt at translating this verse:
A1 Jehovah shall remove men far away
B1 And there shall be a great forsaking within the land.
c1 Yet a tenth shall return
A2 After being removed,
B2 As a great tree, as an oak, when chopped down to a stump,
C3 Yet retains holy seed.
Lines A1 and A2 are meant to be parallel–the covenant people are removed
B1 and B2 speak of an apostasy, the great tree of Israel forsakes the true religion and is chopped down to a stump.
C1 and C2 speak of a remnant returning and the imagery of a tree which retains within itself the possibility of regrowth.
This verse is understandable with a little effort, but the real question is: why is it included at the end of a chapter which details the calling of Isaiah? Is it an answer to Isaiah’s question, “How long shall I preach?” Perhaps the Lord is saying, keep preaching, even after the covenant people are carried away into captivity and there seems there is no hope, for there is still life left in Israel.
Or, as you told Joseph Blenkinsopp: Don’t give up!
Interesting, how you join verses 12 & 13. Could you make a chiastic structure out of the whole answer (vv. 11-13) as Isaiah poses that gut-wrenching question to Adonai?
It is fascinating how some of the translations present the last verse of Isaiah 6:
But yet in it will be a tenth;
And it will return and it shall be burned
Like the terebinth and like the oak
Which in being felled have the stump of them;
The holy seed is its stump. (Jay P. Green’s Interlinear)
But yet a tenth will be in it,
And will return and be for consuming,
As a terebinth tree or as an oak,
Whose stump remains when it is cut down.
So the holy seed shall be its stump. (NKJV)
Yet there will be a tenth portion in it,
And it will again be subject to burning,
Like a terebinth or an oak
Whose stump remains when it is felled.
The holy seed is its stump. (NASV)
Here it is a little more poetical, less bound to the MT . . .
A. And though a tenth remains in the land,
B. it will again be laid waste.
C. But as the terebinth and oak
B. leave stumps when they are cut down
A. So the holy seed will be the stump in the land. (NIV)
Of course, the NEB complicates things, tagging it as a problematic reading . . .
Even if a tenth part of its people remain there,
They too will be exterminated
[like an oak or a terebinth,
a sacred pole thrown out from its place in a hill-shrine].
We need to tell the NEB to not give up.
BinV, I am thankful for that last verse in Isaiah 6. It gives encouraging hope in the midst of dark judgment. Each one of the judgment chapters, usually has words of hope (a remnant theology) to encourage those that will soon be engulfed in the terror because of national rebellion.
I just read “Heavenly Visions and Prophetic Calls in Isaiah 6 (2 Nephi 16), the Book of Mormon, and the Revelation of John” by Stephen D. Ricks. He outlines the prophetic call narratives as such: 1. historical introduction, 2. divine confrontation, 3. reaction, 4. throne – theophany, 5. presentation of a heavenly book, 6. the qedussah, or heavenly song in praise of God, 7. the prophet receives a prophetic commission, 8. the prophet objects or protests, and 9. the prophet is reassured.
The throne paintings of God included in this article—Figure 1. Vision of Isaiah (11th century; Reichenau, Germany) and Figure 2. Die Offenbarung des Johannes (The Revelation of John) by Gertrud Schiller—are nuts in attempting to visually present God. Likewise, the picture in Figure 3 that projects in visual form: heaven, waters above, sluicegates, firmament, a sea surrounding flat lands with Jerusalem in the center, water below, and sheol does not at all give an accurate picture of what we should gather as biblical cosmology in its literal-normative sense.
But Stephen’s quote by Gerhard Hasel on the last phrase in Isaiah 6:13 perked my interest. “The latter phrase is also rendered ‘the holy seed is its stock.’ Gerhard Hasel states that on the basis of Job 14:7-9 it may be gathered that it was common knowledge that the root stock which was left in the ground at the felling of a tree was able to sprout again and thus bring forth new life. The felling of a tree certainly meant its destruction, but not the destruction of the life in the root stock. The root stock is thus the seat of new life.”