In verses 3-8 God the Word draws out why God will not hear His people. Their behavior does not resemble godliness at all, much less godly pursuits that honor Him. Therefore (9), we don't see justice, righteousness, or light, walk like half-dead blind people, stumbling around in the middle of the day and whining about the absence of salvation (10-11). The "speaking voice" has shifted (as of verse 9) to Isaiah, or the collective people of Israel, or is God the Word speaking the truth that all the people hold unspoken in their hearts. Verse 12 is a confirmation of our conscience, of the gentle probing of the Holy Spirit to turn us back to God. Our sins are a result of turning away from God, ignoring truth, and thus the ones that do resist evil make themselves easy pickings for those who continue in it... and this bothered God (13-15). But since no one could do what only God can do, God does. He upholds His righteousness and brings salvation, He comes to repay and redeem (16-21). I read this and, though I don't know if it's connected to the Jewish mindset looking for a Messiah, it sounds like the Messiah to me. The vocabulary sounds militaristic, and establishing a reign that spreads God's glory and fear of Him everywhere, so I can see how people would think that the Messiah was going to be a conquering hero. And God proclaims that these words are going to continue on from generation to generation--proclaiming the fear of the Lord, His greatness now and forever.
On the Sabbath, you should...
On the Sabbath, you should avoid...
... and the result will be...
There is power in the Word of God, if we are willing to take it in. But, more often than not, we only take in what other people say about the Word, a false caricature of who God is and what He's about.
What's funny--funny "I'm gonna ralph," not funny "ha ha"--is that so often we don't reject God at all but the idol that someone has erected and said "this is God." We dissect God, and remove His actions and words from their proper context, and reject the false god that results from it. God out of context is not God at all, but a construction of human reason and logic and feeling and (honestly) whatever opinions happen to be foremost in our thinking at the time. That god isn't God at all. Scripture calls it an idol. And we are not to make any idol to worship or serve (Ex. 20), whether it's a golden calf in the desert or a paragraph that lessens God's greatness.
I've got to sit on that for a while.
Mind + Word of God = Blown