Apostolic Constitutions : You shall not be a hypocrite, lest your "portion be with them." You shall not be ill-natured or proud, for "God resists the proud." "You shall not accept persons in judgment; for the judgment is the Lord's." "You shall not hate any man; you shall surely reprove your brother, and not become guilty on his account"; and, "Reprove a wise man, and he will love you." Eschew all evil, and all that is like it: for he says, "Abstain from injustice, and trembling shall not come close to you." Do not grow angry quickly, or spiteful, or passionate, or furious or daring, lest you undergo the fate of Cain, and of Saul and of Joab. The first of these killed his brother Abel, because Abel was found to be preferred before him with God, and because Abel's sacrifice was preferred; the second persecuted holy David, who had slain Goliath the Philistine, being envious of the praises of the women who danced; the third killed two generals of armies—Abner of Israel and Amasa of Judah. — CONSTITUTIONS OF THE HOLY APOSTLES 7.5 Basil of Caesarea : Why do you grieve, my friend, when you yourself have suffered no misfortune? Why are you hostile to someone who is enjoying prosperity, when he has in no way caused your own possessions to decrease? If you are vexed even upon receiving a kindness [from the object of your spite], are you not quite clearly envious of your own good? Saul is an example of this. He made David's great favors to himself a motive for enmity with him. First, after he had been cured of insanity by the divine and melodious strains of David's harp, he attempted to run his benefactor through with a spear. Then, on another occasion, it happened that he and his army were delivered from the hands of the enemy and saved from embarrassment before Goliath. In singing the triumphal songs commemorating this victory, however, the dancers attributed to David a tenfold greater share in the achievement, saying, "Saul killed his thousands and David his ten thousands." For this one utterance and because truth itself was its witness, Saul first attempted murder and tried to slay David by treachery, then forced him to flee. — CONCERNING ENVY John Chrysostom : But now notice in this incident how much trouble the passion of envy caused: when the king saw this young man enjoying such popularity and the dancing crowds calling out, "Saul's conquests ran into thousands, David's into tens of thousands," he didn't take kindly to their words … but overwhelmed by envy, he now repaid his benefactor with the opposite treatment, and the one whom he should have recognized as his savior and benefactor he endeavored to do away with. What an extraordinary degree of frenzy! What excess of madness! The man who had won him the gift of life and had freed his whole army from the foreigner's rage he now suspected as an enemy, and, instead of the man's good deeds remaining fresh in his memory and prevailing over passion, the clarity of his thinking was dulled with envy as though by a kind of drunkenness, and he regarded his benefactor as his enemy.That is what the evil of this passion is like, you see: it first has a bad effect on the person giving birth to it. — HOMILIES ON Genesis 46.13-14 John Chrysostom : For envy is a fearful, a fearful thing, and persuades men to despise their own salvation. In this way did both Cain destroy himself, and again, before his time, the devil who was the destroyer of his father. So did Saul invite an evil demon against his own soul; and when he had invited, he again envied his physician. For such is the nature of envy; he knew that he was saved, yet he would rather have perished than see him that saved him had in honor. What can be more grievous than this passion? One cannot err in calling it the devil's offspring. And in it is contained the fruit of vainglory, or rather its root also; for both these evils are wont mutually to produce each other. And thus in truth it was that Saul even thus envied, when they said, "David smote by ten thousands," than which what can be more senseless? For why dost thou envy? tell me! `Because such an one praised him?' Yet surely thou oughtest to rejoice; besides, thou dost not know even whether the praise be true. And dost thou therefore grieve because without being admirable he hath been praised as such? And yet thou oughtest to feel pity. For if he be good, thou oughtest not to envy him when praised, but thyself to praise along with those that speak well of him; but if not such, why art thou galled? why thrust the sword against thyself? — HOMILIES ON 2 CORINTHIANS 24.4