The dynamic vision that Isaiah sees of God (Isa. 6) reveals God’s plan to purify his creation in at least three phases. The first phase is the enthronement of a holy God (6:1-4), without which nothing follows. The second phase is for God to obtain and purify a mediator/messenger (6:5-7). The third and final phase is for the purifying message to spread into creation and do its work (6:8-13).
After Isaiah’s purification, God asks, “Whom shall I send, and who will go for us?” (v. 8). Go for us and do what, exactly? Purify his creation. How? By spreading the news that God is on his throne. We often think of the “good news” having a cheerful effect, but that doesn’t happen in this vision. God’s enthronement becomes message of destruction: “‘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.” (Isa. 6:9-10).
This effect might disturb us. Isn’t God’s message one of love and grace? This message seems to be anything but gracious. It condemns. The fact is that the gospel message has a two-pronged effect. It causes some people to rejoice, but it causes most people to harden. In either case, it is doing its job. Isaiah’s vision covers all of creation, the majority of which will be hardened and burnt by the message.
This brings us to the one metaphor that runs through all three phases of the vision: fire. When Isaiah asks how long the message must be preached, God replies “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.” (Isa. 6:11-12). God’s response is essentially, “the message will be preached until there’s nothing left to burn.” God equivocates the message with fire. It is not a fire for the mere sake of destruction, but a fire of purification.
The last section of the passage shows us the scorched earth that the fiery message leaves behind it: “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.” (Isa. 6:13). Virtually everything will be burned up.
It has long been recognized that wildfires renew ecosystems. In fact, it has become its own scientific sub-discipline. Putting out all wildfires may actually lead to a loss of strength and flourishing in an ecosystem! Isaiah 6 is about the fire that God is bringing upon his ecosystem, which is the entire cosmos – his temple. The message is a continuation of that purifying fire, which starts at God’s throne and spreads until there is nothing left, with the exception of one seed. Imagine the entire world completely scorched by fire, but somehow one seed has survived. As impossible as it seems, that seed is the key to renewing the entire ecosystem. In that one seed there is hope for the regrowth of all things.
The message that Isaiah preaches, therefore, is going to burn its hearers. Upon hearing that God has retaken his throne and reigns over the world, many hearts will be hardened. Just as clay hardens under extreme heat, so will many human hearts be hardened under the fire of Isaiah’s message. Remember that the goal of the book of Isaiah is to show how God is going to take an impure, broken Jerusalem and turn it into a glorious, holy city. The vision of Isaiah 6 is the outworking of God’s intentions from the first chapter: “I will turn my hand against you and will smelt away your dross as with lye and remove all your alloy. And I will restore your judges as at the first, and your counselors as at the beginning. Afterward you shall be called the city of righteousness, the faithful city.” (Isa. 1:25-26). Isaiah 6 is the smelting process in action.
If God is going to restore the world to goodness and beauty, then he must have a mechanism for getting rid of the pollutants. Isaiah 6 shows us that God’s message of restoration is itself the cleansing agent. In fact, the gospel message burns everybody. Accepting the gospel means that you will be purified of the worldliness within you. Rejecting the gospel means the world will be purified of you. Once God’s fiery message has filled the world, the purification process will be complete, and God will have a holy seed with which to regrow his creation – the church. The work of Isaiah and all Christians is to embrace and spread that message, and thereby take part in God’s renovation of all things.