In Helaman 13 Samuel the Lamanite is preaching to the Nephites, trying to get them to listen to the glad tidings of the gospel but the people were having none of it. He had to change his tactic and instead of giving them the joyful message of Jesus Christ, he had to tell of the heavy destruction that awaited them if they continued to refuse to repent. What stuck out to me is that Samuel actually gave a pretty specific time frame for the Nephites to change, or else. In verse 9 he tells them that before 400 years have passed, the calamities he is prophesying will come to pass.
What's interesting to me is that he gave a prophesy that would have no direct effect upon the people he was preaching to. Let's face it- if someone came and told you something bad was going to happen...400 years from now...would you really give it much thought? It's not like it was going to have an immediate impact on their lives. I think that as humans our natural inclination would be to blow off such warnings as not being pertinent to us.
That got me wondering why Samuel would be told to prophesy about something that wouldn't happen for many generations down the road. What would be the purpose of preaching to people who already don't want to hear the gospel, and likely aren't going to care what happens 400 years in the future?
Here's what I think: he gave the prophesy not for the people he was physically preaching to, but for their future posterity. He gave it in the hopes that even a few of them would give heed to his words and repent, and then teach the gospel to their children. I think that Heavenly Father knows that sometimes people (especially parents) won't make changes for themselves, but will do so for someone else they love and care about. Think about how many parents want better for their children than what they've had. I don't think that's a modern notion- I think every parent has wanted their child to have a good life. In this case, the only way for the Nephites' posterity to have a good life, or to even have any future beyond the 400 years at all, was for the current and future generations to know and live the gospel. There had to be at least a few who would listen to the prophecy and make sure that it got passed down to their children, grandchildren, and great-grandchildren. Giving this prophecy 400 years before its fulfillment gave the Nephites multiple generations to repent, make changes, and come back to God. It gave them someone else's eternal welfare to think about, so that they couldn't sit back and selfishly think that what they were doing would only hurt themselves. They were encouraged to think longer-term, and to think about how what they did with their life would affect their future generations. Surely there were at least some who listened and whose future families thanked them for their courage, sacrifice, and determination.
By sending Samuel to warn the people 400 years in advance, Heavenly Father was showing His loving compassion and mercy. Although the message ended up having to be a strong warning about destruction and misery, Heavenly Father wanted His children to have the opportunity to do something to change the future for the better. He gave them hundreds of years to build their foundation of faith and to make the changes in their personal, family, and societal lives to save themselves. I think this chapter is a wonderful example of God's long-suffering and patience with His children.