The label good or evil depends on the perspective of the individual and very often the society that the individual is a part of. A Christian may well consider anything related to contacting guides as evil, where a spiritualist can have a very different view.
There is a theory that everything that happens during our time here is arranged by our higher selves before we get here with the full knowledge of the other souls that will share in the experience. This raises an interesting question if something happens to me that I would consider evil can I actually still consider it evil if it is pre planned, done for a reason and with my prior consent, even if I won't understand it until I return to my higher self.
Our experience is what shapes our character and without that experience we may well have held totally different views and taken different paths in life what happens to the other people in our lives also shapes our lives as does anything new that we learn.
Good and Evil with this viewpoint then take a totally different meaning where anything either good or evil is merely an lesson or experience for you or another during their brief stay on this plane.
The idea that dark is evil stems simply from the idea that evil actions are usually hidden, and where do we hide if not in the dark, so the same idea then gives us the light shining the truth on the darkness to expose evil for what it is. note that it is not the dark that is evil but the actions hidden there.
If we are to subscribe to the above theory then there is no such thing as good or evil only experience, everything is one, we simply choose to go through certain trials in an effort to grow or to help others grow.