1 John 3:11-12, 14-16

For this is the message which you have heard from the beginning, that we should love one another; not as Cain, who was of the evil one and slew his brother. And for what reason did he slay him? Because his deeds were evil, and his brother’s were righteous.

We know that we have passed out of death into life, because we love the brethren. He who does not love abides in death. Everyone who hates his brother is a murderer; and you know that no murderer has eternal life abiding in him. We know love by this, that He laid down His life for us; and we ought to lay down our lives for the brethren.