10 And therefore, beloved brethren, the Lord, taking thought for this risk, that none should fall into the snare of death through jealousy of his brother, when His disciples asked Him which among them should be the greatest, said, “Who soever shall be least among you all, the same shall be great.” He cut off all envy by His reply. He plucked out and tore away every cause and matter of gnawing envy. A disciple of Christ must not be jealous, must not be envious. With us there can be no contest for exaltation; from humility we grow to the highest attainments; we have learned in what way we may be pleasing.
And finally, the Apostle Paul, instructing and warning, that we who, illuminated by the light of Christ, have escaped from the darkness of the conversation of night, should walk in the deeds and works of light, writes and says, “The night has passed over, and the day is approaching: let us therefore cast away the works of darkness, and let us put upon us the armour of light. Let us walk honestly, as in the day; not in rioting and drunkenness, not in lusts and wantonness, not in strifes and jealousy.” If the darkness has departed from your breast, if the night is scattered therefrom, if the gloom is chased away, if the brightness of day has illuminated your senses, if you have begun to be a man of light, do those things which are Christ's, because Christ is the Light and the Day.
Source: The Treatises of Cyprian (New Advent)