6 Considering which things, beloved brethren, let us with vigilance and courage fortify our hearts dedicated to God against such a destructiveness of evil. Let the death of others avail for our safety; let the punishment of the unwise confer health upon the prudent. Moreover, there is no ground for any one to suppose that evil of that kind is confined in one form, or restrained within brief limits in a narrow boundary. The mischief of jealousy, manifold and fruitful, extends widely.
It is the root of all evils, the fountain of disasters, the nursery of crimes, the material of transgressions. Thence arises hatred, thence proceeds animosity. Jealousy inflames avarice, in that one cannot be content with what is his own, while he sees another more wealthy. Jealousy stirs up ambition, when one sees another more exalted in honours. When jealousy darkens our perceptions, and reduces the secret agencies of the mind under its command, the fear of God is despised, the teaching of Christ is neglected, the day of judgment is not anticipated.
Pride inflates, cruelty embitters, faithlessness prevaricates, impatience agitates, discord rages, anger grows hot; nor can he who has become the subject of a foreign authority any longer restrain or govern himself. By this the bond of the Lord's peace is broken; by this is violated brotherly charity; by this truth is adulterated, unity is divided; men plunge into heresies and schisms when priests are disparaged, when bishops are envied, when a man complains that he himself was not rather ordained, or disdains to suffer that another should be put over him. Hence the man who is haughty through jealousy, and perverse through envy, kicks, hence he revolts, in anger and malice the opponent, not of the man, but of the honour.
Source: The Treatises of Cyprian (New Advent)