10 So we can see who God’s children are and who the devil’s children are. These are the ones who are not God’s children: those who don’t do what is right and those who do not love their brothers and sisters in God’s family.
11 This is the teaching you have heard from the beginning: We must love each other.
12 Don’t be like Cain. He belonged to the Evil One. Cain killed his brother. But why did he kill him? Because what Cain did was evil, and what his brother did was good.
13 Brothers and sisters, don’t be surprised when the people of this world hate you.
14 We know that we have left death and have come into life. We know this because we love each other as brothers and sisters. Anyone who does not love is still in death.
15 Anyone who hates a fellow believer is a murderer. And you know that no murderer has eternal life.
16 This is how we know what real love is: Jesus gave his life for us. So we should give our lives for each other as brothers and sisters.