1 John 3:12-16

and not be like Cain, who was of the evil one and murdered his brother [Abel]. And why did he murder him? Because Cain’s deeds were evil, and his brother’s were righteous. Do not be surprised, believers, if the world hates you. We know that we have passed out of death into Life, because we love the brothers and sisters. He who does not love remains in [spiritual] death. Everyone who hates (works against) his brother [in Christ] is [at heart] a murderer [by God’s standards]; and you know that no murderer has eternal life abiding in him. [Matt 5:21-23] By this we know [and have come to understand the depth and essence of His precious] love: that He [willingly] laid down His life for us [because He loved us]. And we ought to lay down our lives for the believers.