I personally do not believe that there is anything that "is" evil. Evil is not something that truly exists. I understand the concept of evil, but I understand it not as something that exists, but as something that lacks something else that does truly exist, namely good. I liken evil to darkness, as many people do.
Darkness is not something that truly exists. It is merely a concept, a construct of the mind, a word we use to describe a situation wherein there is no light. Darkness is nothing more than the absence of something. It is the absence of light. If you take away light, what you have in it's place is nothing at all. What you have is no different than if you were to take away all matter. If you should take away all matter, what you have in it's place is nothing at all. What you are left with if you should take away all light is no different than what you are left with if you should take away all matter.
God is Good. All that is good is of God. This is my opinion. It's what I believe. If a mountainside should collapse on a village killing everyone in the village, nothing necessarily bad, or evil has happened. If it were God's will for a mountainside to collapse on a village killing everyone in the village, then it is not evil, or bad, but rather it is good. If it is of God, it is good. If it is not of God, it lacks good. We certainly call that bad, or evil, but as I said, it is not, for bad and evil do not exist, it is only a concept to describe situations that lack good. If what we do lacks the goodness of God, we most certainly can call ourselves evil, but that is only because we lack the goodness of God.