^11-13 For the original command, as you know, is that we should love one another. We are none of us to have the spirit of Cain, who was a son of the devil and murdered his brother. Have you realised his motive? It was just because he realised the goodness of his brother’s life and the rottenness of his own. Don’t be surprised, therefore, if the world hates you.

Love and life are inter-connected

^14-15 We know that we have crossed the frontier from death to life because we do love our brothers. The man without love for his brothers is living in death already. The man who actively hates his brother is a potential murderer, and you will readily see that the eternal life of God cannot live in the heart of a murderer.