From his promise that they shall beat their swords into plowshares, and their spears into pruninghooks¹ through his imagery of the wolf shall dwell with the lamb, and the leopard shall lie down with the young goat² to this ending, the prophet Isaiah offers his people (and us) a vision of an idyllic future. Is this book a prediction of the coming of Christ? We can't know for sure, only perhaps strongly believe, but given that the peace of which it speaks clearly did not come at the time of Jesus renders that interpretation somewhat unimportant. We are still waiting.

Yes, Jesus also promises a better tomorrow, but both prophets are very clear that this is a conditional promise. We can bring the kingdom of heaven to earth but we must do our part too, and over the past few thousand years we have failed in that, prioritising war and oppression over peace and goodwill. Worshipping the one true God is by far the hardest thing humans are asked to do. We fail over and over, seeking out all sorts of idols instead—seeking the easier, softer way. God would like to give us the gift of the kingdom, but while we turn away God's hands remain tied. Life will improve through working on better relationship, not through waiting around for magic. God and human: we are in this together.

¹ Isaiah 2:4
² Isaiah 11:6