You never really get a sense of how bad things were spiritually in Judah until you see what it took to get them back on track. Even after the massive cleansing ceremony (which takes place in the previous chapter) here we get a better picture of just how bleak it was throughout the whole land of Judah and the surrounding tribes. They finally have a king who is the most like David (their greatest king ever) who wants to bring the whole land back to the place they should be spiritually. What jumps out at me is the fact that so many of the people of Israel thought what Hezekiah was doing was a complete joke. His messengers were not well received by the people of the land.
but they laughed them to scorn, and mocked them. -- 2 Chronicles 30:10
This is a clear picture of how deeply ingrained they were into the pagan culture. This was not just a few years of straying away from the true God, but generations of mind-numbing and heart-chilling infestation. They were at the point where this whole one true God thing was absolutely absurd for them. They probably thought of it as backward thinking and closed mindedness. They probably looked down of the few holdouts who still held true to the old faith. They had truly "moved on." Sound familiar? Even the priest and the levites must have turned cold as they were not able to perform their duties at full capacity.
and the priests and the Levites were ashamed, and sanctified themselves... -- 2 Chronicles 30:15
They had come so far -- almost to the point of no return. Hezekiah has to over a prayer of atonement for all the people as they struggle to do what is right in their weak spiritual state. I see this period in the history of Judah as the final spark of goodness . . . sort of like what happens sometimes before an incandecent light bulb blows out. You get that final surge of bright light and then -- poof! This is true for Judah as well during the time of Hezekiah. They return to that full brightness that was during the time of David and Soloman for just a brief period. We all know what happens next -- poof!