Who among you fears the Lord
    and obeys the word of his servant?
Let the one who walks in the dark,
    who has no light,
trust in the name of the Lord
    and rely on their God.
11 But now, all you who light fires
    and provide yourselves with flaming torches,
go, walk in the light of your fires
    and of the torches you have set ablaze.
This is what you shall receive from my hand:
    you will lie down in torment.

Derek Kidner calls this ‘the pivot of life or death’. Here are the alternatives, you can have light from God or follow your own light; you can walk in His light or light your own fires. The latter route doesn’t lead anywhere good. Sorrow is always the ultimate end of unrepented/unforgiven sin. Kidner points out also, however, that these words may anticipate the New Testament teaching on punishment after death.

We are living in days when all too many theologians and preachers are lighting their own fires. They mean to warm themselves and their flocks by them, no doubt. But fire can devour as well as cheer. In 2 Peter 3:16, Peter writes about the apostle Paul, saying:  

”His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.”

”The Servant is not simply to be admired or wondered at; he is to be obeyed (10). In short, describing his own discipleship the Servant has shown them what God requires of all his people: not empty profession, but wholehearted, costly obedience…The Servant and the challenge that he brings force a separation between the true and the false, the righteous and the wicked, the saved and the lost – among those who profess to be God’s people!” Barry Webb: ‘Isaiah’, p.199.