'Evil' in the Bible

I am writing to you, fathers,because you have come to knowthe One who is from the beginning.I am writing to you, young men,because you have had victory over the evil one.

I have written to you, children,because you have come to know the Father.I have written to you, fathers,because you have come to knowthe One who is from the beginning.I have written to you, young men,because you are strong,God’s word remains in you,and you have had victory over the evil one.

unlike Cain, who was of the evil one and murdered his brother. And why did he murder him? Because his works were evil, and his brother’s were righteous.

We know that everyone who has been born of God does not sin, but the One who is born of God keeps him, and the evil one does not touch him.

We know that we are of God, and the whole world is under the sway of the evil one.