1 John 3:10–15 (NKJV)
John has just finished speaking of the manner of love with which the Father has loved us. Having sent His Son as the propitiation for our sins, God has demonstrated tremendous love for the people of the world, making a way for our salvation. While John ended the last passage with a command to love one another, he elaborates on that command here in this passage.
10 In this the children of God and the children of the devil are manifest: Whoever does not practice righteousness is not of God, nor is he who does not love his brother. 11 For this is the message that you heard from the beginning, that we should love one another, 12 not as Cain who was of the wicked one and murdered his brother. And why did he murder him? Because his works were evil and his brother’s righteous.1 John 3:10-12
John is very direct and clear in the judgment he offers concerning the characteristics and actions of those who are redeemed and those who are not. Here, he identifies sinners and saints as children of God and children of the devil, respectively. The criteria for this designation is two-fold: do you practice righteousness, and do you love your brother? If you practice righteousness, you are of God. If not, you are not of God. Also, if you do not love your brother, you are not of God. God’s righteousness and love are hallmarks of the Christian life. The message of Christ from the beginning is that Christians should love one another. Christians should shunt the example of Cain, who was evil and killed his brother. Abel was the righteous brother, and Cain was evil and his works were evil. Do not follow the example of Cain, refusing righteousness and hating his brother.
13 Do not marvel, my brethren, if the world hates you. 14 We know that we have passed from death to life, because we love the brethren. He who does not love his brother abides in death. 15 Whoever hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.1 John 3:13-15
In the same thought line as love and hate, John discusses the hatred of the world for the church and its members. He tells them of this certainty, even instructing the reader not to marvel at the world’s hatred for them. However, he additionally instructs that believers have passed from death to life, evidenced in the fact that we love the brethren. If you harbor hate against your brother, and do not love your sister, then you abide in death. If you hate your brother or sister, you are as guilty as a murderer. Murderers have no hope of eternal life outside of repentance. Therefore, John is saying that hatred also demands repentance. Do not harbor hate or resentment in your heart. Love is the hallmark of Christian existence, and Christians should not hate.
So often, emotions get in the way of holiness, and Christians end up hurt, sometimes harboring resentment or even hatred. This is a trick of the enemy to divide the body of Christ and create emotions that will preclude man’s ability to walk with God rightly. Ask God to take you from resentment to love. Reconcile yourself to God and to your fellow man. John says, “We know that we have passed from death to life, because we love the brethren.“