In the year that King Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and the train of his robe filled the temple. Above him stood the seraphim. Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew. And one called to another and said:
“Holy, holy, holy is the Lord of hosts; the whole earth is full of his glory!”
And the foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke. And I said: “Woe is me! For I am lost; for I am a man of unclean lips, and I dwell in the midst of a people of unclean lips; for my eyes have seen the King, the Lord of hosts!”
Then one of the seraphim flew to me, having in his hand a burning coal that he had taken with tongs from the altar. And he touched my mouth and said: “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.”
And I heard the voice of the Lord saying, “Whom shall I send, and who will go for us?” Then I said, “Here am I! Send me.” And he said, “Go, and say to this people:
“‘Keep on hearing, but do not understand; keep on seeing, but do not perceive.’ Make the heart of this people dull, and their ears heavy, and blind their eyes; lest they see with their eyes, and hear with their ears, and understand with their hearts,and turn and be healed.” Then I said, “How long, O Lord?”And he said: “Until cities lie waste without inhabitant, and houses without people, and the land is a desolate waste, and the Lord removes people far away, and the forsaken places are many in the midst of the land. And though a tenth remain in it, it will be burned again, like a terebinth or an oak, whose stump remains when it is felled.” The holy seed is its stump. (Is. 6)
Isaiah after having seen the Living God and having his sin symbolically forgiven was then re-commissioned for service unto God. It must here be noted that an experience with God aways results in transformation of the person and especially for service unto God as in the case of Isaiah. Those who have had an experience with God cannot remain the same in their sins and apathy towards the needs of the world. Whosoever claims to have experienced God yet remain the same in their sin and apathy is a liar. Or as the Apostle John wrote, "Whoever says “I know him [Christ]” but does not keep his commandments is a liar, and the truth is not in him" (1 Jn. 2:4)
In verses 8-13 of chapter 6, Isaiah's recommission occured. The LORD called out for people to bring His message, and Isaiah acting in submission to God volunteered (v. 8). He was then given the worst message ever to be proclaimed in the entire Bible; a message of hardening and destruction which he was nonetheless to proclaim. He was given a message that was intended not to save but to confirm wicked Israel in her unbelief. Israel was to be judicially hardened through Isaiah's proclamation of judgment, and are to be told that they would harden in their unbelief. Though they hear, they cannot understand. Seeing, they cannot perceive (v. 9). God made their hearts dull and blind their eyes (v. 10a) to the reality of judgment and devastation. Scripture then states that God does so in order that these people will not repent and turn to God and therefore be healed (v. 10b) .
The last statement surely refutes the false notion that God loves and desires everyone to be saved. God does not desire the salvation of these Israelites and in fact have already consigned them to everlasting judgment. In fact, God actively hardens them through the means of Isaiah's message. So what are we to make of this?
It must be stated that such a hardening is judicial, in that it is an act of punishment. We can see in the preceding chapters how wicked and rebellious Israel is, and therefore this is not to mean that God actively damns people. Rather, they have already condemned themselves by their wickedness, and therefore it is God's will to punish them. Such a hardening is necessary for punishment since it is in the nature of Man to make an appearance of repenting from virtually anything when trouble comes upon them; doing anything that would save their lives. Such an hardening therefore is necesary so that they would not repent even if doing so would be beneficial to their well-being, so that God can pour out His wrath upon them.
Regardless, such a message is still shocking. This also shows that there is such a thing as a point of no return, in which those who pass that point are forevermore cut off from the (earthly) possibility of being saved at all. This is also seen in the teachings found in the book of Hebrews
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt. (Heb. 6:4-6)
The warning in Hebrews of course is that true apostates have absolutely no possibility of salvation. And that is what Israel as a nation have degenerated into, as God has destined their destruction without any mercy.
Isaiah was told to proclaim his message of judgment until God's judgments and wrath have been poured out over Israel. Israel was to be destroyed, her land left desolate without inhabitants (v. 11), her people taken away in exile and her many places forsaken (v. 12). Yet even in such promises of destruction there is still hope. For God has promised that they would not be completely destroyed; God will not destroy His wayward people completely but there will always be a renmant chosen by grace (cf Is. 1:9), symbolized by the tenth remaining in the land (v. 13) which will still experience hardship however (burned again), spillover from the terrible judgment upon the wicked in Israel. The elect remnant would be the holy seed as the stump, in anticipation of the regrowth of the Covenant people of God as manifested within the Church.
So therefore, as we come before God, let us come to Him in all reverance and holy fear. Let us prepare to experience Him through the Spirit working in us by His Word, and that we might come to the glorious knowledge of the worth and glory of our Lord Jesus Christ. And with that let us go forth to do good works which God has prepared for us to do (Eph. 2:10), in order to serve God and His people. Amen.