Within the disputations of Isaiah 40-55 YHWH is constantly engaged in a wisdom debate with Israel. Essentially, by appealing to his role as Creator, and therefore the maintainer and guide of history, YHWH is arguing that the way he has set for Israel is the best way. YHWH is defending his wisdom against Israel's protestations. Within the context of 40-55 it is likely that YHWH is saying that he chose Cyrus of Persia to act as the messiah to Israel, Cyrus would be the agent to bring them out of exile. But Israel rejected Cyrus, refusing to recognise that salvation could come from such a figure. As a result the return from exile is long delayed.
The essential problem is that Israel in exile, although no longer worshipping idols, is still idolatrous because she is treating YHWH like an idol. Israel refuses to trust YHWH's wisdom, refuses to recognise that YHWH would act in such new and unexpected ways, and thereby limits YHWH to acting like the idols. And, because they treat YHWH like an idol, they put their trust in the same things that those around them trust in. Therefore, when YHWH does act Israel refuses to recognise such actions as divine – and she only goes deeper into exile as a result.
It seems to me that this is also one of the fundamental problems facing our contemporary western church. Although churchgoers are not actively worshiping idols they are essentially treating Jesus as an idol, refusing to recognise the radical ways he breaks into history. Instead they choose to trust in other things – the financial security provided by a steady job, the illusory safety provided by a suburban neighbourhood, the future hope provided by RRSPs, and so on and so forth. While claiming to worship Jesus, very few people actually trust Jesus for anything significant in their day to day lives. And that means treating Jesus like just another idol. It also means that, for all the Christian talk about longing to see God break-in in radical new ways, most Christians aren't willing to recognise moments when God does – because, as a general rule, God breaks-in in ways that we don't want to call divine. God breaks-in in ways that requires us to transfer our trust to God's actions and agents, instead of the standard people and things that our culture trusts in. Simply put, many Christians don't really trust God's wisdom, and that makes it damn near impossible to follow Jesus.