In the Psalms we often see David, the individual feeling hopeless. Here it is a whole nation. But it was not God's intention to leave them in their hopelessness. He saw their misery, and wanted to revitalise the sad discouraged community of Israel. There are many groups, churches, communities and nations today who need to know that the Lord can make dead bones live.
Jeroboam was an evil king, and during his reign many abominations happened, (1 Kings 12) but the Lord had a plan to put things right, and he sent this unnamed prophet to foretell what would happen 300 years later. In the next verse the prophet declared that the altar would split apart as a sign that this word was from the Lord. Read the rest of the chapter and see that this did happen immediately in front of Jeroboam who lifted his hand to arrest the prophet, but his hand withered and would not move!