1 John 3:9-12 KJV

[9] Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God. [10] In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother. [11] For this is the message that ye heard from the beginning, that we should love one another. [12] Not as Cain, who was of that wicked one, and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother's righteous.