This Gospel passage is another example of “Don’t ask Jesus a question if you have an ulterior motive.” If you do, Jesus is going to ask you a question instead and follow it up with a story that is going to illustrate and undermine the foundation of your motive. “Whenever Jesus is asked a question, he always turns the situation around so that it is he who asks the deeper question and the questioner who is challenged and questioned.”
This man is only interested in his own problems; he sees in Jesus only a teacher with authority and prestige who can help sort out his case (cf. Deut 21:17). He is a good example of those who approach religious authorities not to seek advice on the way they should go in their spiritual life, but rather to get them to solve their material problems. Jesus vigorously rejects the man’s request—not because he is insensitive to the injustice which may have been committed in this family, but because it is not part of his redemptive mission to intervene in matters of this kind. 
The Catholic Commentary on Sacred Scripture says that Jesus’ answer hints at his identity:
The question echoes the one put to Moses: “Who has appointed you ruler and judge over us?” (Exod 2:14), which Luke includes twice in Stephen’s speech in Acts in showing that, although some Israelites rejected Moses, God appointed him as their redeemer (Acts 7:27, 35). Similarly, Jesus will be rejected but will bring about God’s redemption (Luke 21:28; Acts 3:13–14).
Jesus then warns the man asking the question, “Take care, and be on your guard against all covetousness, for one’s life does not consist in the abundance of his possessions.”
Brant Pitre explores the underlying Greek word pleonexia, which is translated usually as greed or covetousness.
It does mean covetousness, it does mean greed, but one of the most prominent dictionaries in the New Testament defines it as following: “the state of desiring to have more than one’s due; insatiableness.” So pleonexia, it means a kind of super abundance or desire to have more than you need, which of course is what greed is all about. 
Jesus then tells him a story now known as the Parable of the Rich Fool, which is unique to Luke. A rich man who has put both God and neighbor out of the picture. A man without thankfulness and gratitude other than patting himself on his own back. He is lost in the Epicurean pleasures to just “relax, eat, drink, be merry.” “There is nothing better for a person under the sun than to eat and drink and be glad” (Ecclesiastes 8:15).
However, God calls him a fool, a term Jesus earlier applied to the Pharisees (Luke 11:40). “The fool says in his heart, / ‘There is no God’” (Ps 14:1). Effectively, the rich man behaved as if there is no God, since he put his trust in his possessions rather than in God. He is an atheist in practice.
Examples of the rich man illustrated in this parable are easy to find in real life. The self-made man, the man who believes in himself. These traits have so often been seen as admirable in our society. Unfortunately, if we look in the mirror, we can see aspirations not much different from those illustrated in this parable.
John Bergsma makes the point:
The American Dream is fundamentally incompatible with the Gospel of Jesus Christ. A life whose goal is 2.5 children and a spacious ranch house in the suburbs looks essentially different from a life whose goal is eternal communion with Jesus Christ and his saints. Bourgeois Christianity that regards more than two kids as “unrealistic” because they are “too expensive,” that thinks twenty dollars in the offering plate is a favor to God, that can’t be bothered with a homily longer than ten minutes or a Mass longer than sixty, that is repulsed by the idea of the religious life for oneself or one’s children, is really a form of unconverted Christianity, which is no Christianity at all.
This is the core of the anti-Gospel. To go out into the whole world to exploit it for yourself for your own sense-pleasures. This is very similar to the parable of Lazarus and the Rich Man, blindness to those around us in need.
Jesus ends by implying that the only riches that endure are the ones that we lay up in treasure towards God.
19 “Do not lay up for yourselves treasures on earth, where moth and rust6 destroy and where thieves break in and steal, 20 but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. 21 For where your treasure is, there your heart will be also. (Matthew 6:19–21)
In contrast to the disordered love of possessions and ego, St. John of the Cross in his commentary on his poem “The Spiritual Canticle” shows us what the true treasure is:
Whether the heart has been truly stolen by God will be evident in either of these two signs: if it has longings for God or if it finds no satisfaction in anything but him, as the soul demonstrates here. The reason is that the heart cannot have peace and rest while not possessing, and when it is truly attracted it no longer has possession of self or of any other thing. And if it does not possess completely what it loves, it cannot help being weary, in proportion to its loss, until it possesses the loved object and is satisfied. Until this possession the soul is like an empty vessel waiting to be filled, or a hungry person craving for food, or someone sick moaning for health, or like one suspended in the air with nothing to lean on. Such is the truly loving heart. 
Finishing up with two quotes from the Church Fathers.
“A person who lives as if he were to die every day—given that our life is uncertain by definition—will not sin, for good fear extinguishes most of the disorder of our appetites; whereas he who thinks he has a long life ahead of him will easily let himself be dominated by pleasures”
For in vain he amasses wealth who knows not how to use it. Neither are these things ours which we cannot take away with us. Virtue alone is the companion of the dead, mercy alone follows us, which gains for the dead an everlasting habitation. 
- Peter Kreeft, Food for the Soul: Reflections on the Mass Readings Year C
- Navarre, Saint Luke’s Gospel (2005)
- The Gospel of Luke, Catholic Commentary on Sacred Scripture, Rev. Pablo T. Gadenz
- Catholic Productions, Commentaries by Brant Pitre
- The Word of the Lord: Reflections on the Sunday Mass Readings for Year C – John Bergsma
- The Collected Works of St. John of the Cross
- Photo by Ben White on Unsplash
- Peter Kreeft, Food for the Soul: Reflections on the Mass Readings Year C ↩
- Navarre, Saint Luke’s Gospel (2005) ↩
- The Gospel of Luke, Catholic Commentary on Sacred Scripture, Rev. Pablo T. Gadenz ↩
- Catholic Productions, Brant Pitre ↩
- The Word of the Lord: Reflections on the Sunday Mass Readings for Year C, John Bergsma ↩
- The Collected Works of St. John of the Cross, ICS Publications ↩
- Athanasius, Adversus Antigonum ↩
- St. Ambrose, Archbishop of Milan, A.D. 374. Catena Aurea: Commentary on the Four Gospels, Collected out of the Works of the Fathers: St. Luke ↩