I can't believe I missed this thread!
Good and evil are words used in both propaganda and religion. They are a simplistic way to describe a person's actions and to categorize them without just cause. Life is a morally gray area, in all aspects. Of course, those with perhaps a skewed view of the world, perhaps mentally ill, can become what people would call evil, however what you may see as wrong, they have been able to come up with just cause to do such acts. Is it evil of you to have dirty thoughts of your co-worker? Your mother's friend? No. They are your thoughts. However acting on those thoughts can be seen as morally wrong, or evil. It is too easy to lump together people who have a skewed perception as evil, since a lot of them can be helped and brought to a place that doesn't make them a threat to others. You can't say that when perhaps broke, no job, nothing to fall back on, that you haven't at least thought of robbing a store, or trying to swindle someone out of money. It's not inherently evil to have these thoughts, it's not evil to even act on them. Human kind's most basic instinct is to survive, at whatever it takes. Sadly life is a series of purchases nowadays. It takes money for some people to feel safe, secure, and it takes money nowadays to even live.
It's the classic thief and the beggar. Who is more likely to be punished? Who is also more likely to survive?
Morality is the complex explanation of good and evil. It's easy to say someone is good when you look at them, they have a good job, good family, good house... but what's to say that person won't turn around and murder his wife's boss for sleeping with her...