Matthew 19:16-26

And behold, a man came up to him, saying, “Teacher, what good deed must I do to have eternal life?” And he said to him, “Why do you ask me about what is good? There is only one who is good. If you would enter life, keep the commandments.” He said to him, “Which ones?” And Jesus said, “You shall not murder, You shall not commit adultery, You shall not steal, You shall not bear false witness, Honor your father and mother, and, You shall love your neighbor as yourself.” The young man said to him,“All these I have kept. What do I still lack?” Jesus said to 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.” When the young man heard this he went away sorrowful, for he had great possessions. And Jesus said to his disciples, “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.” When the disciples heard this, they were greatly astonished, saying, “Who then can be saved?” But Jesus looked at them and said, “With man this is impossible, but with God all things are possible.”

This account also appears in Mark 10:17-27 (where it says that Jesus loved the young man) and in Luke 18:18-27 (where we learn that the young man was a ruler, perhaps a Pharisee)

good deed - trying to enter the kingdom by his own merit

"Jews of the time believed that performing some single good act would guarantee salvation." (Ryrie)

Why do you ask me about what is good? - As if to ask, 'Have you really thought this through?' Jesus was making the point that only God is good. If the young man thought Him good, that mean he was referring to Jesus as God. Was he ready for that?

"In addressing Jesus Christ as 'Good Master,' the young man evidently meant to do Him honor, but Jesus points out the fact that only God is good. All men are sinners (Romans 3:12). Therefore, if Jesus were only a man, He would not be good, in this absolute sense. If truly good, then He is God. After this solemn declaration, the Lord Jesus took the inquirer up on his own ground. The law promised life to those who kept it (Leviticus 18:5; Galatians 3:12). So the Lord answered, 'If thou wilt enter into life, keep the commandments.' This declaration was designed to show the man his inability to obtain life on that ground, for if conscience were active, he would realize he had already violated the law. He saith unto Him, 'Which?' This was clearly an attempt to evade the full force of the Lord’s words. In reply, Jesus quoted five of the principal commandments and concluded by summing up all of those that refer to our duties to our fellow-men by quoting from Leviticus 19:18, 'Thou shalt love thy neighbor as thyself.' It would indicate an unawakened condition of soul if one could face all these and now plead guilty." (Ironside)

Jesus listed the commandments (vs 18-19) that were displayed outwardly. The young man claimed to have kept those.

sell what you possess and give to the poor - Jesus showed that the young man hadn’t kept the commandments to love God with all his heart or to love his neighbor as himself.

"The man was being asked to prove his claim to have kept the commandments, especially the one that says 'You shall love your neighbor as yourself' (v. 19).  His unwillingness to do so belied his claim (v. 20) and showed him as a sinner in need of salvation." (Ryrie)

"The man’s response demonstrated that he was not righteous, for he was unwilling to fulfill the second table of the law and love his neighbor as himself. His response also revealed that he did not fulfill the first table of the law that forbade one to have gods above the true God. One’s god is what he serves, and this man loved and served his wealth." (Pentecost)

a camel to go through the eye of a needle - "Christ’s use of the word for a surgeon’s suturing needle indicated that His references to a camel and a needle were to be taken literally. The popular explanation that the eye of a needle referred to a small gate within the large city gate has no historical basis. Christ was not teaching that it is difficult for one who trusts in riches to enter the kingdom. He was showing that it was utterly impossible for one who trusts in riches to enter the kingdom. Such a teaching seemed inconceivable to the disciples who had been brought up on the philosophy that riches were a sure sign of divine pleasure and an evidence of God’s blessing. If the rich whom God loved and blessed and with whom He was pleased could not enter the kingdom, what chance was there for the multitudes? Christ responded, 'With man this is impossible, but not with God; all things are possible with God' (Mark 10:27)." (Pentecost).

"In this proverbial expression, Christ does not say that a rich man could not be saved (v. 26), but only that, for him, it is more difficult, since such a person seldom senses his personal need as readily as a poorer man does." (Ryrie)

rich person - not necessarily one who has riches, but one who trusts in riches

The Lord’s point was that no man can gain eternity by his own merit or effort (v 26). It is impossible. But he can gain it through God.