Notwithstanding other takes on Isaiah 55, I have more to say. Here is part of Isaiah 55:
so is my word that goes out from my mouth:
It will not return to me empty,
but will accomplish what I desire
and achieve the purpose for which I sent it.
12 You will go out in joy
and be led forth in peace;
the mountains and hills
will burst into song before you,
and all the trees of the field
will clap their hands. 13 Instead of the thornbush will grow the pine tree,
and instead of briers the myrtle will grow.
This will be for the LORD's renown,
for an everlasting sign,
which will not be destroyed."
I think we all agree that this is about God's redemptive work in the world. Most (all?) of you think that redeeming nature, and more specifically not the one we have right now, is not part of God's plan - its "all about us". And it is clear from this passage that there is a degree of metaphor here (even I, who I think you have to admit, am taking all these various texts more "literally" than the rest of you, do not believe that hills will burst into song).
But, I do suggest it is a very odd poetic style indeed to write such material about what you guys think is a redemption from which nature is excluded, and yet set redeemed mankind in a context that overflows with references to nature.
It simply does not make sense to have the redeemed man "go out in joy" into a "natural world" that is described as if it is celebrating as well, even though, on your view, it will be toasted.
Not to mention this oddity: The writer claims that God's word will achieve its redemptive purpose and not return empty. Yet, if you guys are right, it is only the man who frolics in the nature that is redeemed. So I will assert that you have Isaiah basically saying this:
"Even though my first statement in this text sets the reader up to expect a following explanation of what it means for God's redemptive word to not return empty, I really do not intend you to believe all this stuff about nature seeming to share in this redemption. It is only the man that is redeemed.
So, even though I set this text up with a theme of redemption, and even though a myrtle replacing a brier is a strong image of redemption that harkens clearly back to Genesis 3 and the curse pronounced on nature - with specific allusions to weeds, I do not intend the reader to see things this way at all. It is only the man who is redeemed."
I find that a very curious way to see this text. I think it is far far more reasonable, if you approach this text with an open mind to both positions, to see it as including nature within the scope of redemptive activity.