In verse 7, Samuel notes that he had been previously sent to declare repentance to the Nephite people, but they would not receive him. Verses 5 and 6 suggest why. This wasn’t a kind message from a soft-hearted God. This was a message of impending destruction, “yea, heavy destruction awaiteth this people, and it surely cometh to this people, and nothing can save this people save it be repentance.”
The doom had two timeframes of fulfillment. One of them was four hundred years in the future. Dr. Mark Wright suggested that it was far enough away that it was hardly a prophecy that any of the listeners took seriously, or thought that it would impact their lives. It was, however, an important prophecy precisely in that it was for four hundred years. That time period was called a baktun in Maya, and it was emotionally similar to our thousand years. Thus, it was a sacred and symbolic timeframe.
The second doom, however, would come much sooner. Samuel is prophesying within six years of the Savior’s birth, and by the time of Christ’s death, the Nephite nation would dissolve into tribes, and their whole physical world would be subject to physical destruction. That part of the destruction, many of those present would live to see.