Yin Yang

I don't think there is an international standard of morals. For example, in a cannibalistic society it seems perfectly fine to eat fellow human beings, but in the US, it is most definitely not acceptable. Take the "Zombie Man" as an example. In 2012, a man attacked another man in Florida and "ate his face off". I'm sure we all remember that incident... Either way, whether it's a mental disease, drug induced behavior, or just the way you were born, we all have a different perception of how we, and the people around us, should act.
No on to good and evil. I do not believe that a person or thing can be completely good or evil. If you think an idea is bad/evil, you have to keep in mind that it must benefit some people. The idea might not be in the interest of others and the majority of people involved will be negatively impacted, but it's important to realize that the minority thing of it as a good thing, and the majority will think of it as a bad thing. Literally everything in existence has good and bad, which bring me to Yin Yang. The idea of Yin Yang is that dark and light (good and evil) are interconnected in the world and as they interrelate, they give rise to each other to keep the balance of the world. Basically, good cannot be without the existence of evil; and it makes sense because if there was no evil in the world, we would acknowledge/pick out the good, and would have no appreciation for the good happening around us.