After explaining the history and future of the House of Israel, Jacob concludes his sermon by pleading to the people, with all his heart that they repent. Chapter 6 has some wonderful verses on repentance.
Their Own Place
Verse 3 reminds me of Alma's counsel to his son when he taught him that "all things shall be restored to their proper order" (Alma 41:4). He went on to instruct his son that "if their works are evil they shall be restored unto them for evil" (see Alma 41:2-6). Jacob teaches us that those who repent not in this life will be "cast out into their own place." What this means is that those who desire evil all the days of their life will remain on the earth and will be burned with the world when it burns with fire.
Repent With Full Purpose of Heart
Next in verse 5, Jacob implores, “I beseech of you in words of soberness that ye would repent, and come with full purpose of heart, and cleave unto God as he cleaveth unto you. And while his arm of mercy is extended towards you in the light of the day, harden not your hearts.” Heavenly Father loves us so much, but he cannot force us to come unto Him. He will constantly “be there” for us, but we must choose to come back to him. We also cannot half-heartedly repent of our sins and turn to God. We must turn to him "with full purpose of heart." In other words, we must give all our heart, might, mind and soul.
My brother Richard spoke at my missionary farewell. In his talk he related a story about a feast a king held for his subjects. The king sent out invitations to all the people in the kingdom. Everyone was invited, but there was one stipulation that must be met before a person was allowed into the feast … every person must bring water. The king did not specify how much water a person should bring, but just that they needed to bring water. The day of the feast came and the people began to arrive. Every person admitted brought water … some brought the water in buckets, some in cups, some in thimbles and some in large barrels. The king's men took each container, dumped the water into a pool and admitted the guest. The people enjoyed a day of feasting and activities. At the end of the feast, the king stood and thanked his guests for attending his feast. He informed them that when they departed each of their containers would be returned to them … not empty, but full of gold, jewels and riches. Those that brought water in thimbles received a timble-sized portion of riches. Those that brought water in barrels received barrel-sized portions of riches.
And so it is with our allegiance and loyalty to God in His kingdom. The greater our loyalty and diligence in keeping the commandments and serving in his kingdom, the greater our reward (see Alma 41:15).
In verses 11 and 12, Jacob effectively summarizes what every prophet has attempted to teach the people. He admonishes the Nephites to repent, enter in the gate and continue on until they've obtained eternal life. And then he succinctly teaches us to be wise.