Jesus told the Pharisees that wanted to know when the kingdom of God would appear on Earth that it had already arrived, but could not be detected with the physical eye because it exists on the inside of a person (Luke 17:21). Jesus compared believers to little children and said, “Whosoever shall not receive the kingdom of God as a little child, he shall not enter therein” (Mark 10:15). Some of the Jews may have thought they could earn or deserved admittance into God’s kingdom. When he was asked, “What shall I do that I may inherit eternal life?” Jesus said, “If thou wilt enter into life, keep the commandments” (Matthew 19:17). The point Jesus may have been making was that there were actually two ways you could enter into God’s kingdom, you could receive it as a little child or inherit it by keeping all of God’s commandments. The rich man that wanted to inherit eternal life told Jesus “All these I have kept. What do I still lack? Jesus told him, ‘If you would be perfect, go, sell what you possess and give to the poor, and you will have treasure in heaven; and come, follow me'” (Matthew 19:20-21, ESV).
The rich man that wanted to inherit eternal life probably didn’t understand that God’s kingdom wasn’t something he could expect to enjoy in the afterlife without investing in it while he was alive. Wealth in God’s kingdom was something that Jesus measured by perfection. When he told the rich man he could be perfect, Jesus meant he could be completely happy, perfectly content (G5046/G3772). In order for that to be possible, the rich man had to get rid of his earthly possessions, the things that were keeping him focused on the physical rather than spiritual realm in which God exists. When the man heard Jesus’ criteria for perfection, “he went away sorrowful, for he had great possessions” (Matthew 19:22). In other words, he was extremely rich and wanted to enjoy his wealth while he was still alive. “And Jesus told his disciples, ‘Truly, truly I say to you, only with difficulty will a rich person enter the kingdom of heaven. Again I tell you, it is easier for a camel to go through the eye of a needle than for a rich person to enter the kingdom of God” (Matthew 19:23-24, ESV).
The difficulty Jesus was referring to that would make it possible for a rich person to enter the kingdom of heaven was most likely a sort of selflessness or personal denial that a religious person was incapable of, partly because he would want credit for his effort. Jesus’ disciple realized the impossibility of a person with material wealth wanting to give that up in order to obtain spiritual riches. They asked Jesus, “Who then can be saved?” (Matthew 19:25). Jesus explained to his disciples that it was God’s responsibility to save someone, not the individual himself. He said, “With men this is impossible, but with God all things are possible” (Matthew 19:26). Jesus demonstrated this directly when he gave up his life to save humanity. It was not Jesus’ human nature that drove him to willingly die on the cross. Jesus told his twelve apostles, “See, we are booing up to Jerusalem, and everything that is written of the Son of man by the prophets will be accomplished. For he will be delivered over to the Gentiles and will be mocked and shamefully treated and spit upon. And after flogging him, they will kill him., and on the third day he will rise” (Luke 18:31-33, ESV).