{12} Not as Cain, who was of that wicked one, and slew his brother. {13} And wherefore slew he him? Because his own works were evil, and his brother's righteous.

(12) An amplification taken from the contrary example of Cain who slew his brother.

(13) A short digression: Let us not marvel that we are hated by the world for doing our duty, for such was the condition of Abel who was a just person: and who would not rather be like him than Cain?

People's New Testament

3:12 Not as Cain, who was of that wicked one. Cain, who hated and slew his brother (Ge 4:8), is an extreme type of children of the devil. This hater and murderer is condemned far more severely in the Scriptures than the disobedient Adam.

Wesley's Notes

3:12 Who was of the wicked one - Who showed he was a child of the devil by killing his brother. And wherefore slew he him - For any fault? No, but just the reverse; for his goodness.

Jamieson-Fausset-Brown Bible Commentary

12. who-not in the Greek.

of that wicked one-Translate, "evil one," to accord with "Because his own works were evil." Compare 1Jo 3:8, "of the devil," in contrast to "of God," 1Jo 3:10.

slew he him? Because his own works were evil, and his brother's righteous-through envy and hatred of his brother's piety, owing to which God accepted Abel's, but rejected Cain's offering. Enmity from the first existed between the seed of the woman and the seed of the serpent.

Matthew Henry's Concise Commentary

3:11-15 We should love the Lord Jesus, value his love, and therefore love all our brethren in Christ. This love is the special fruit of our faith, and a certain sign of our being born again. But none who rightly know the heart of man, can wonder at the contempt and enmity of ungodly people against the children of God. We know that we are passed from death to life: we may know it by the evidences of our faith in Christ, of which love to our brethren is one. It is not zeal for a party in the common religion, or affection for those who are of the same name and sentiments with ourselves. The life of grace in the heart of a regenerate person, is the beginning and first principle of a life of glory, whereof they must be destitute who hate their brother in their hearts.

Matthew Henry's Whole Bible Commentary

Verses 11-13

The apostle, having intimated that one mark of the devil's children is hatred of the brethren, takes occasion thence,

I. To recommend fraternal Christian love, and that from the excellence, or antiquity, or primariness of the injunction relating thereto: And this is the message (the errand or charge) which you heard from the beginning (this came among the principal parts of practical Christianity), that we should love one another, v. 11. We should love the Lord Jesus, and value his love, and consequently love all the objects of it, and thereupon all our brethren in Christ.

II. To dissuade from what is contrary thereto, all ill-will towards the brethren, and that by the example of Cain. His envy and malignity should deter us from harbouring the like passion, and that upon these accounts:-1. It showed that he was as the first-born of the serpent's seed; even he, the eldest son of the first man, was of the wicked one. He imitated and resembled the first wicked one, the devil. 2. His ill-will had no restraint; it proceeded so far as to contrive and accomplish murder, and that of a near relation, and that in the beginning of the world, when there were but few to replenish it. He slew his brother, v. 12. Sin, indulged, knows no bound. And, 3. It proceeded so far, and had in it so much of the devil, that he murdered his brother for religion's sake. He was vexed with the superiority of Abel's service, and envied him the favour and acceptance he had with God. And for these he martyred his brother. And wherefore slew he him? Because his own works were evil, and his brother's righteous, v. 12. Ill-will will teach us to hate and revenge what we should admire and imitate. And then,

III. To infer that it is no wonder that good men are so served now: Marvel not, my brethren, if the world hate you, v. 13. The serpentine nature still continues in the world. The great serpent himself reigns as the God of this world. Wonder not then that the serpentine world hates and hisses at you who belong to that seed of the woman that is to bruise the serpent's head.