Pope Francis recently weighed in on the economics of inequality. As a professional in that field, I could respond by detailing his errors of fact and reasoning. Maybe some other time. For now, I think that if the pope can pronounce on economics, then it’s only fair that I -- a full-time preacher of economics -- should be allowed to opine on his grasp of Christian morality.

By dwelling on inequality, the pope is promoting envy. The Catholic Church, I had always understood, disapproves of envy, deeming it one of the seven deadly sins. I would have expected Francis to urge people to think of themselves in relation to God and to their own fullest potential. Encouraging people to measure themselves against others only leads to grief. Resenting the success of others is a sin in itself.

The first sin outside the Garden of Eden was Cain’s slaying of his younger brother, Abel, out of envy that the Lord had accepted Abel’s offering but not his. God told Cain: “If you act rightly, you will be accepted; but if not, sin lies in wait at the door.” (Genesis 4:7) Worry about your standing with God, not about what others have or don’t have.

The Ten Commandments conclude with: “You shall not covet your neighbor’s house. You shall not covet your neighbor’s wife, his male or female slave, his ox or donkey, or anything that belongs to your neighbor.” (Exodus 20:17)

The New Testament reports that the early church “had everything in common” (Acts 4:32), a situation into which two of the deadly sins quickly intruded. Greed first, with Ananias and Sapphira lying to protect their property. (Acts 5:1-11) Then envy, as “the Hellenists complained against the Hebrews because their widows were being neglected in the daily distribution.” (Acts 6:1) What was the response of the apostles? That this petty envy was a problem, but beneath their concern: “It is not right for us to neglect the word of God to serve at table.” (Acts 6:2)

While Jesus repeatedly preached against the love of riches, he was urging people to respond to a call to God and to become “rich to God.” It was not an appeal for people to resent the riches of others and obsess about material inequality. Jesus, when asked to remedy inequality, turned the focus back on envy and greed.

“Someone in the crowd said to him, ‘Teacher, tell my brother to share the inheritance with me.’ He replied to him, ‘Friend, who appointed me as your judge and arbitrator?’ Then he said to the crowd, ‘Take care to guard against all greed, for though one may be rich, one’s life does not consist of possessions.’” (Luke 12:13-15)

I am all for reducing poverty. I’ve spent most of my career working on that issue. I’m all for economic growth that’s inclusive and that raises the productivity and incomes of the poorest. I’m for social justice and attacking inequities. I’m against the privilege and corruption that denies opportunities to others. I am all for fairness, not least in economic affairs, and for state intervention when necessary to serve that purpose.

What I’m against is talking about “inequality” as if that term denoted any of those concerns. Poverty matters; injustice matters. Mere inequality is beside the point.

In the course of my professional work against poverty I met Larry Page and Sergey Brin, co-founders of Google Inc. They are each worth about $30 billion, according to the Bloomberg Billionaires Index. The economic inequality between them and me is vast. Should I resent them for this? Should I also envy them for being smarter than I am? Younger? Better looking?

The Web needed a better search engine. In a fiercely competitive market Page and Brin invented a product that by 2012 was being used 5 billion times a day -- for free. With no advantages other than brains, perseverance and the luck of being in the right place at the right time, they created a product with colossal social value and figured out how to make it pay. My coveting their wealth is a sin.

It’s argued most wealth isn’t like this -- that it comes not from creating value in a competitive market but from abuse of power, manipulation of markets or the entrenched advantages of inherited wealth. A lot of wealth surely does arise in that way. But this isn’t an argument against my point; it’s precisely my point. When we complain about inequality in the abstract we aren’t thinking about what is or isn’t fair or just or equitable. Those distinctions turn on the process that caused the inequality. So let’s stop talking about inequality and talk directly about the things we ought to care about: absolute deprivation, abusive power, rigged markets and unearned privilege.

I have an Indian friend who is a Dalit and used to be a Naxalite guerrilla. (That’s a violent Maoist rebel group that operates in parts of India.) Nowadays he’s an ardent proponent of freer markets as a means to social justice. Staying at his village home one night I asked him what changed his mind. He said, I just woke up one morning in the jungle and asked myself: “Why am I so angry if someone else eats an ice-cream cone?” My friend saw firsthand the risks of preaching envy, and repented.

If Francis stopped encouraging people to break the Tenth Commandment, he would have more time to instruct us on the dangers of greed and avarice, to deplore injustice and unfairness, and to call for every effort to relieve poverty. And, if I may be allowed to say so, he would be following the example of the apostles if he left the serving of tables to others and preached the word of God.

(Lant Pritchett is professor of the practice of international development at the Kennedy School of Government at Harvard University and co-author of “Moving Out of Poverty: Success From the Bottom Up.")

To contact the writer of this article: Lant Pritchett at Lant_Pritchett@harvard.edu.

To contact the editor responsible for this article: Clive Crook at ccrook5@bloomberg.net.