I won't even make you click a link, so you're more likely to read it:
10 Who among you fears the LORD
and obeys the word of his servant?
Let him who walks in the dark,
who has no light,
trust in the name of the LORD
and rely on his 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.
Everyone is stumbling around in the dark. Some trust God to provide light, and he does. They wait patiently, and God provides.
Some find a way to light their way. They produce flame of their own accord. The interesting thing here is that they actually succeed. They're no longer stumbling around in the dark. The only difference is the final judgment.
That's the scary part. Because while often I have experienced the frustration and futility of doing it my own way, "in my own strength," instead of relying on God, He seems to be saying here that he might sometimes let us achieve in our own strength. We just get to reap the rewards of his judgment.
This would be scary, except that God is gracious. And, to be honest, I think it's really not very hard to determine if I'm trusting God with my life efforts or not. I'm finding that checking my motivation is really not as hard as I always thought it was. Being motivated to actually do that, well, that's another story.