9 No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God.
10 This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not God’s child, nor is anyone who does not love their brother and sister.

More on Love and Hatred

11 For this is the message you heard from the beginning: We should love one another.
12 Do not be like Cain, who belonged to the evil one and murdered his brother. And why did he murder him? Because his own actions were evil and his brother’s were righteous.
13 Do not be surprised, my brothers and sisters,a if the world hates you.
14 We know that we have passed from death to life, because we love each other. Anyone who does not love remains in death.
15 Anyone who hates a brother or sister is a murderer, and you know that no murderer has eternal life residing in him.
16 This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters.
17 If anyone has material possessions and sees a brother or sister in need but has no pity on them, how can the love of God be in that person?
18 Dear children, let us not love with words or speech but with actions and in truth.
19 This is how we know that we belong to the truth and how we set our hearts at rest in his presence: