In this chapter, the LORD delivers Israel and Samaria from the army of Aram.
Structurally, this story is a chiasm. It begins with a prophetic declaration that Israel would be delivered and that the disbelieving royal official would see it but not eat of it, and it ends with very nearly the exact same text. The rest of the story is the fulfillment of Elisha's prophecy, with both deliverance for the people of Israel and death for the man without faith.
The basic framework of this story is that the LORD delivers Israel through his supernatural power, and then we get to see four different reactions to that from Elisha, the king of Israel, the king’s faithless officer and the desperate lepers. This should give us an idea of Israel's society at the time, as well as a picture of how people respond to divine deliverance in general.
As we might expect, Elisha announces the LORD’s deliverance and responds with the faith that we typically see from him. I feel like Elisha is a bit of one-dimensional character in these stories; more often than not, Elisha stands in as a proxy for God rather than as a person in his own right.
The king responds with skepticism, reluctant to believe that Israel was actually delivered, but he acquiesced to send a few scouts out to search for the Arameans. In this way the king seems to follow in the pattern of Ahab, opportunistic and taking advantage of God's deliverance, but never really following the LORD.
The king’s officer responds with disbelief, saying that it was impossible for God to save Israel, and because of this Elisha cursed him to see the LORD’s deliverance but that he would not share in it. This is similar to the faithless spies in Numbers 13 who entered the promised land but said that it was impossible for Israel to conquer it. They saw the promised land, but God cursed them that they could not enter it because they did not respond with faith.
The lepers were camping out at the gate of the city. Because of their skin disease, they were not permitted to live within the city walls, which is part of the law (evidently, part of the law that was still followed). They were in a desperate situation, suffering from the famine afflicting the city but forced to live outside the protection of the walls and more vulnerable to attack from the Arameans. After discovering the empty camp and taking a few moments to enrich themselves, they realize that they have an obligation to share the good news with the entire city. I see the lepers’ reaction as primarily being self-interest. They go out to the Arameans not in faith or faithlessness, but as an attempt to save themselves, and then they go inform the city because the realized they could be punished by the king (or perhaps God) for not sharing the news with the rest of the people. In this way, I see the lepers as reacting in a way similar to the king of Israel, Joram. Both Joram and the lepers are happy to receive the LORD's salvation, but for lack of a better word, they do not respond to it. I don't think the lepers or Joram have done anything sinful per se, but God's mercy demands a response and I don't see it here. They are saved for the moment, but they are not transformed.
So there are these four main groups, one that responds with faith, one that responds with no faith, and two groups that respond with a sort of opportunistic neutrality, neither accepting nor rejecting God's activity but taking advantage of the situation as it evolved.