Matthew 19

16 Most of the people that came to Jesus followed Him and listened. It is likely that this man had heard something like, "Jesus knows the answers to all questions," so he barges in and starts asking (Mark 10:17). As will be revealed, the man did not come to listen and follow.

The Jewish religious system is based on obedience to a vast array of laws. However, theirs is not the only religious system that believes they can get to heaven by doing "good things." However, the basis of our relationship with God is faith, not works. Thus, those who approach God this way are left with an empty uncertainty because they do not know how many good works are enough.

The man is not only seeking the answer to this problem, but he also reveals his lazy spiritual nature. Obedience to all the laws is burdensome. The man asks if there is just one thing he can do to guarantee heaven. Probably, he would like to do that one thing so he can be assured of heaven and no longer be burdened with obedience to the rest. Once he does the "one thing" he could go on with his life and do whatever he pleases.

By the end of this dialogue, the man will be shown there are two things he must do: repent from sin and follow Jesus.

17 Some have claimed that Jesus denies that He is good in this verse. That is not true. Jesus is asking whether the man believes He is God or not. Other verses more explicitly state that Jesus is God, so we can deduce that Jesus is good.

If a person could keep the commandments of Moses without ever sinning he could go right to heaven. However, since we are all contaminated by sin, it is impossible to keep the law perfectly. In fact, there is no one qualified for heaven based on his own merits. However, Jesus died for our sins, and when we believe in Him we are credited with His perfection. Thus, we enter heaven through Jesus.

18 Whether he meant to admit it or not, the man says he could not possibly keep them all, so he asks Jesus to reduce the list.
20 Jesus listed the social commands, but left out the commands concerning a person's relationship with God. He probably did this on purpose, knowing that the man would have said he had kept any commandment that Jesus had listed.

The man knew that there must be more to it than this, so he continues to ask Jesus about it. He was likely looking for that one "great" act that would ensure heaven. If he had ever heard Jesus teach, he missed the point that people can not earn heaven. They must have help from God. A person who comes to know God has a complete life change, and do not rely on some act of goodness that they once did.

21 Jesus points to the two things that are hindering the man. First, he made money his god, and was in constant violation of the first commandment. He needed to repent of this sin. Second, he needed to follow Jesus for the rest of his life. These are the basic principles that will ensure anyone of heaven: repent and believe in Jesus.
22 Many people are not willing to give up their old sinful lives for a better life with God. This is very shortsighted since the possessions of heaven are worth far more than any collection of possessions on earth. The blessings of heaven are much better than the temporary gratification we find in this life.
23 Wealth can be a great facilitator for good, but it can also become a trap if a person trusts more in his money than he does in God (Deu 8:10-20, Prov 30:8-9).
24 The camel was the largest creature that lived in the region, and the eye of a (literal) needle was the smallest space something could pass through (Wycliffe). The idea was to convey the utter impossibility of a rich man entering the kingdom of God.
25 This saying astonished the disciples. They had been told all their lives that material wealth was a sure sign of God's blessing. If a rich man could not be saved, then who could be? It is true that God promised to meet the needs of His followers and in some instances even promised wealth, but nowhere is it said that wealth or poverty is an indicator of one's spiritual well being (Deu 7:12-15, 1 Ki 3:10-14).
26 Jesus emphasizes that no one can get into heaven based on his own merit, actions, power, or possessions. Even a rich man can not buy his way into heaven since God, who owns the universe, has no need for wealth (Job 41:11, Psa 50:7). It is forgiveness from God that comes through faith that allows one to enter heaven (John 3:16-17, Eph 2:8-9).
27 The disciples had left their occupations and their possessions to follow Jesus. They were poor. If the wealthy could only enter heaven by God's grace and forgiveness, what would be in store for them? Would those who gave up everything have a greater reward?
28 Jesus indicates that the disciples would indeed have a special reward. Their assignment would be to first continue Jesus' ministry and spread the good news about Him. On Judgement Day, it appears that Jesus will delegate His authority to judge. The disciples would specifically be assigned to judge the twelve tribes of Israel. At least part of that judgement would occur during their lifetimes as they pronounced Jesus' message and rebuked those who would not believe.

Jesus mentions twelve thrones. This does not mean He had in mind that Judas Iscariot would be sitting on one of those thrones. What is unclear is whether Matthias, whom the disciples chose (Acts 1:15-26), or Paul, whom Jesus specifically appeared to, will fill Judas' vacated throne.

29 This appears to be a more general reward for the believers. The most important reward will be eternal life in God's presence. The other items listed should not be considered limits on the reward. The point is that those faithful to God will inherit a reward that far exceeds what they gave up to follow Jesus.
30 Jesus explained that those who give up everything (i.e., they have become last in this lifetime), will receive the most important positions in heaven (i.e., they will become first).