St. Basil The Great, a doctor of the Church and founder of Eastern Monasticism wrote and preached in defense of the Divinity of Christ and the truths of the Catholic faith.
He wrote that our jealousy of those who have more than us isn't so much born of a resentment of them for what they have, but a belief that our unhappiness springs from our lack of the things we covet. It is our envious discontent that causes our suffering.
In Dante's Purgatorio , the envious are gathered together clothed in sackcloth and have their eyes sutured closed with metal wires. They all have little or nothing and cannot envy what they cannot see.