A rich young man, the rich and salvation, temporal and eternal rewards- Read (Matthew 19:16-29) (Mark 10:17-30) (Luke 18:18-30)
To Peter's question as to what would be their (disciples) gains for having left everything and followed him, Jesus spoke about eternal and temporal rewards. Jesus promised his disciples that when God restores the order of all things (as we read in Revelation 21), they would be given prominent positions; they would he highly honored and respected. The twelve tribes of Israel could mean "all of God's redeemed people." "Judging" would not mean literal judging, but being esteemed among the redeemed. The word "regeneration" here means "new birth" or "renewal" or "restoration".
For those who have left house, or brothers, or sisters, or father, or mother, or wife, or children, or land, for Jesus' sake, and for the sake of the gospel, will receive one hundred times (manifold) now in this time, houses, brothers, sisters, mothers, children, and land, (Mark adds "with persecutions"). By this Jesus meant, that the loss of personal relationship with family members would be compensated by God giving the sacrificing believer many more spiritual relationships. In earthly terms, persecutions would not be counted as a reward, but Jesus said, "Blessed are they which are persecuted for righteousness' sake: for theirs is the kingdom of heaven." (Matthew 5:10)
Finally, Jesus ended by saying, "But many who are first will be last ; and those that are last will be first." In this context, where Jesus is dealing with "the rich who trust in their riches", it means that the rich of the world, who are considered first by the world, had yet to get on the path to eternal life, because of their love for riches (they became last), while the disciples who are poor and considered of no worth or last by the world, had gained access to heaven and were well on their way to inherit eternal life (they became first).