I don't believe in evil. Still, that doesn't keep me from writing about it and creating characters who are loathsome in their behavior and thoughts.
I recently had a dialogue with someone regarding developing a foil for a protagonist, which led to a discussion about the nature of evil.
"What makes a good villain?" I asked.
"What if a person isn't religious?"
"It doesn't matter. Evil is evil."
Is it that simple? Is there an absolute yardstick for evil? Or does it depend on which side of the road you are standing?
Does a suicide bomber see himself as evil? Does a general, whose actions cause the death of thousands of civilians, see himself as evil? I know that a person who believes in God would state that according to their world view that certain acts are evil. Okay, but what about the other person who believes in the same God, but believes their actions are guided by a religious point of view?
The point? In writing about villainy, someone can either paint a character in broad strokes so that the reader has no question about that person's morality, or else one can paint three dimensional characters, each character with his or her own moral compass. In that situation, the reader might have to question his or her own views and make a decision about whether that person is entirely evil or not.
I recently read "A Game of Thrones" by George RR Martin. While I criticised the novel for being too "soap operish" in its plot construction, I will give Martin credit for creating characters that were complex. One of the most foul of these characters is a boy suddenly thrust into the role of monarch. It would be easy to dismiss him, branding him as pure evil, but Martin helps us see how the child emerged as a tool for the ambitious mother, and how he is in many ways a victim of his upbringing. Does it it any way excuse his behavior within the book? No. No more than any current political figure can be excused for their actions. However, by giving the character depths, by rendering him more human, we have something more powerful than a cardboard representation of "good" and "bad".
I'm not saying a writer shouldn't occasionally create an old fashioned monster with a handle bar moustache and nasty demeanor, but the three dimensional villain makes a deeper literary footprint. Who is more menacing, the Lord of Mordor (remote, unknowable, an abstract representation of evil), or Hannibal Lecter (the soft spoken, dignified, manipulative serial killer)?