ACC ~ 1 John 3 v10

BY THIS IT MAY BE SEEN. DIDYMUS THE BLIND: Since a person who walks in righteousness is born of God, it follows that someone who is so born will love his brothers. Someone who lacks righteousness because he does not practice it, but instead hates his brother, is not born of God. COMMENTARY ON 1 JOHN.

CHILDREN OF THE DEVIL. CYRIL OF JERUSALEM: The chief author of sin is the devil, the begetter of all sin. Before him, no one sinned. Nor did he sin because he was by nature prone to sin (since in that case the responsibility for his sin would lie with his Creator). Rather, being created good he became a devil by his own free choice, receiving that name from his willed action. Though he was originally an archangel, he became a slanderer (diabolos), because of his slandering. CATECHETICAL LECTURES 2.4.

NOT OF GOD. ANDREAS: Love is the mark of sinlessness, and hate is the mark of sin. Since the person who walks in righteousness is born of God, it follows that someone who is so born will love the brothers, whereas someone who does not have this new birth will not do so. Rather he who hates his brother is not of God. CATENA.

ONE WHO DOES NOT LOVE A BROTHER. BEDE: Love is the great divide between the children of God and the children of the devil. Those who have love are children of God, and those who do not are children of the devil. Have anything else you like, but if you lack this one thing, then all the rest is of no use to you whatsoever. On the other hand, you may lack almost anything else, but if you have this one thing, you have fulfilled the law. ON 1 JOHN.

1 Jn