A few thoughts on this passage...1. John writes here about giving up the PRACTICE of sinning, that is to say the commitment to a pattern of doing or thinking wrongly..someone cuts you up on the motorway, it may be your practice to race back and cut them up or it may be that you sit and simmer and think of all kinds of murderous thoughts against the anonymous driver! For alcoholics, they have to learn to give up the practice of going into shops which sell alcohol and building up a new set of friends who don't frequent pubs...where is it you go or what friends do you have who encourage you to sin? A school yard where you meet other parents who gossip about others or denigrate the teachers? A cycling club where they speak with misogyny and swear frequently...? 2. John writes about Cain and Abel. Cain killed his brother because, we are informed at the beginning of Genesis, his sacrifice was not acceptable to God whereas Abel's was. We aren't informed that Cain was doing evil. It appears that John has got to that conclusion either by divine inspiration or by working backwards from the fact of the murder seeking to discover a motive. A passage in one of the Old Testament apocryphal books, the Wisdom of Solomon, reminds the reader that the sight of a good man make evil people hate them and want to kill them. Think of Joseph and his brothers! 3. The proof of who is a child of God is in their love for their fellow brother or sister according to John. And how can we tell what love is? We have the example of Jesus Christ as a perfect standard to challenge us. 4. The only way to stand confidently before God when we meet Him on Judgement Day is to truly love. Think of those you have known who have truly loved. They may be outside conventional Christian circles, but they have loved. The Radio Five presenter, Nicky Campbell, was adopted as a baby and he regards that as the best thing that has ever happened to him, because the woman who adopted was such a loving woman, not just to him, but to all she fostered or adopted.