Envy has been present in the world since sin first infected humanity. After committing the original sin that caused the fall of humanity, Adam's sons and daughters were weakened and are prone to commit other sins.
Genesis tells us what happened to Cain and Abel: Both offered their first fruits to God, but the Lord was not pleased with Cain, so, out of envy and resentment, he killed Abel (Gen 4:1-16).
The Catechism of the Catholic Church adds:
The tenth commandment requires that envy be banished from the human heart. (...) Envy can lead to the worst crimes. (cf Gn 4:3-7; 1 Kings 21:1-29). “Through the devil's envy death entered the world.” (cf. Wis 2:24)
The diabolical sin par excellence
The Catechism goes on to explain:
Envy is a capital sin. It refers to the sadness at the sight of another's goods and the immoderate desire to acquire them for oneself, even unjustly. When it wishes grave harm to a neighbor it is a mortal sin:
St. Augustine saw envy as "the diabolical sin" "From envy are born hatred, detraction, calumny, joy caused by the misfortune of a neighbor, and displeasure caused by his prosperity."
Pope Francis' take
In his 2024 general audience series on vices and virtues, the Holy Father suggested that envy is rooted in a false concept of God.
We do not accept that God has his own “math”, different from ours. For example, in Jesus’ parable about the workers called by the master to go into the vineyard at different times of the day, those in the first hour believe they are entitled to a higher wage than those who arrived last; but the master gives everyone the same pay, and says, “‘Am I not allowed to do what I choose with what belongs to me? Or do you begrudge my generosity?’ ” (Mt 20:15).
Do you suffer from envy?
To find out, ask yourself (and answer honestly) the following hypothetical questions:
1. When someone close to you succeeds in some endeavor, do you:
(a) rejoice and wish them well?
(b) get angry and want them to go on to fail, because you think they don't even work that hard?
2. A friend is marrying a wealthy person you both know. Do you:
(a) sincerely congratulate your friend?
(b) talk badly about them to their fiancé(e) to make them change their mind?
3. Your neighbor bought a new car. Do you:
(a) think they’re doing well at work and deserve the upgrade?.
(b) tell your friends that your neighbor’s money must be ill-gotten and that they’ll pay the consequences later?
4. A co-worker you didn't like was fired, even though they were very efficient. Are you
(a) very sorry for what happened to them, and you pray for them?
(b) very happy and think they got what they deserved?
5. A person close to you tells you that they’re going on a trip abroad because they won a prize. Are you:
(a) surprised and happy for them, hoping they’ll continue to be lucky in whatever they do?
(b) sad because such things don't happen to you, even though you’re a better person than they are, and you hope their luck changes?
Results
If most of your answers were with item B: you are an envious person, and need to work on loving others more.
If most of your answers were with item A: nourish that positive attitude so that none of your answers would be item B.
And put into practice the remedy given by the Church in the Catechism: “The baptized person combats envy through good-will, humility, and abandonment to the providence of God.” (CEC 2554).
And heed these words of Pope Francis in the recent audience (Feb. 28, 2024):
Envy is an evil that has not only been investigated in the Christian sphere: It has attracted the attention of philosophers and wise men of every culture. At its basis is a relationship of hate and love: one desires the evil for the other, but secretly desires to be like him. The other [person] is the epiphany of what we would like to be, and what we actually are not. His good fortune seems to us an injustice: Surely, we think to ourselves, we would deserve his successes or good fortune much more!
[...] We would like to impose our own selfish logic on God; instead, the logic of God is love. The good things He gives us are meant to be shared. This is why St. Paul exhorts Christians, “Love one another with brotherly affection; outdo one another in showing honor” (Rom 12:10). Here is the remedy for envy!