‘Marvel not, brethren, if the world hates you. We know that we have passed out of death into life, because we love the brethren. He who does not love dwells in death. Whoever hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.'
Cain represented the world in its rebellion against God. So we should not be surprised, if we are true Christians and seek the will of God, that the world hates us, or is against us. For the world rebels against the will of God. And yet it does not like to be reminded of the fact. It wants to be told that it is fine, and those who dwell on earth want to be told that there is nothing wrong with the way that they as men live and the way that they behave. So if any dare to do otherwise they will find themselves hated. If they speak out they will be vilified. The world becomes inflamed against them.
‘We know that we have passed out of death into life, because we love the brethren.' This is the crucial factor. Whom we love depicts what we are. Those who love the brothers who are true to the faith (in contrast to those who love the world - 1 John 2:15) reveal that they too are true to the faith, and thus that they have passed from death to life. They have eternal life. They are citizens of Heaven (Philippians 3:20). They have ‘crossed over' from death to life (compare John 5:24).
‘He who does not love dwells in death. Whoever hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.' On the other hand those who do not so love dwell in death. They have not passed from death to life. They are dead in trespasses and sins (Ephesians 1:1). They are dead while they live (1 Timothy 5:6). To live is to have been given new life by God and to walk in God's way and will, according to the highest good. To be dead is to be living according to the course of the world, to live meaninglessly (1 Timothy 5:6). Their failure to love those who declare the truth reveals them for what they are, those who reject the truth, those who reject the will of God. And their attitude towards them makes them the equivalent of murderers. Here John has the words of Jesus in mind whereby one who hates is a murderer (Matthew 5:21-22). We often find in John such assumptions of the recognised Christian tradition as expressed in the Gospels.
‘Whoever hates his brother is a murderer.' That is, is like Cain, rebelling against God's ways. But hate here is not a consuming hatred, (although it can become that), it is to have an aversion, in this case to the truth, and therefore to those who hold the truth.
And the result of this is that they cannot have eternal life dwelling in them, for they have within them the seed of murder, they are murderers at heart. And the one who is so ready to continue in such a thought reveals by that fact that he sees and walks contrary to the will of God and is therefore lost. (This refers to the set attitude of mind and not the instant thought. Things can happen that make even the best of us sometimes feel like ‘murdering' someone).