Verses 5, in contrast, describes the great contrast with this glory with the human condition. Isaiah realizes that he is unworthy.
Verses 6-7 give us reassurance. Since we are not worthy, God has a way of redeeming us, of overcoming our sin. Isaiah's guilt was removed.
Verse 8 reminds us why we need this redemption. We have a task. Isaiah accepted his call.
(much of this from or inspired by Isaiah 1-39, by Walter Brueggeman)
How much of this is repeated in a typical church service? Do we recognize an overwhelming divine presence? Do we recognize our own sinfulness? Can we receive redemption? If so, what are we prepared to do with it?