I think most decent folk, when thinking about the evil in the world, wish they could do something about it. However, most people seem to have a very broad idea of what constitutes "evil". And they are right...evil has been summed up as "knowing what's right and still doing what's wrong" and "sin" (thank you, Facebook friends!). I have heard others describe it as "anything that opposes God" or "anything that opposes good". These definitions are right...but they are huge. If it behooves me to do something about evil, I find it pretty overwhelming to think of my foe as "anything and everything that is the opposite of good"! So...perhaps I should narrow my definition a bit.
Maybe I cannot fight every strand of evil that is in the world. But I can do something about some of the evil. A couple other definitions my friends provided of evil were "malicious, deliberate and conscious immoral act, it's where the motive is to harm or cause destruction ...it is a very selfish act" and "evil is when you deliberately do something that you know is wrong with no remorse." These strike me as a little more specific...they involve malicious motive, destruction, selfishness, and a lack of remorse.
I think I would follow the "destructive" idea a little further. Destructive of what? Maybe life...or anything that sustains life...or dignity...or inalienable rights (life, liberty, and the pursuit of happiness)...? The more specific one's definition of evil, the more likely one will know where to start in combating it. Perhaps I cannot fight evil that is one huge foe consisting of everything I think of as "bad," but I can do something about human trafficking, or human rights, or child abuse, or providing clean water and food for the oppressed to whom these "luxuries" are denied.
A person's definition of evil seems to be intricately connected with his or her values....
In reference to the idea of evil as "selfish," I would say this is an important point. Sometimes people joke about people of differing political parties being the enemy, or people with very different values. I don't think this is true. It comes down to motive. In the United States, for instance, both Republicans and Democrats stand by their party's values because they believe those values are what will be best for the citizens of this country. Their motives are the same...neither are evil. Evil comes into play when my needs become more important than yours. Evil is when I am willing to sacrifice your needs...or you...in order to meet my own.
When it comes down to it, I think most of us would agree on the things that are truly evil...things like genocide, slavery, sadism.... But if we learn how to articulate the things we believe are evil...perhaps we will learn more about what we truly value, and perhaps we will realize what we can do to help others who suffer because of the evil in the world. And maybe we can better keep from contributing to it.