I was looking for verses to send those people who are going to have a FUN exam. And I saw this verse.

This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all. If we claim to have fellowship with him yet walk in the darkness, we lie and do not live by the truth. But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin.

1 John 1:5-7