"I have other issues with the label "evil", especially as it has come to be used in our largely secular society. It is often used in a dynamic way, as in "the Devil has the best tunes", so that it becomes something aggressive and almost seductive."

Interesting account on the usage of (in this case) evil, and the lack of depth due to the common use of it.

When it comes to humans, I think psychopathy best describes "evil". It's more defined and thus harder to abuse.

I guess it's like pornography; you know it when you see it.

What about when something bad happens, whether it's natural or man-made, it's always "God's" will?

It is very convenient and maybe self preserving to label something we don't understand as evil just so we know to avoid perceived threat. However, the blind leading the blind in this matter creates mass hysteria or paranoia.
Subjected to this fear, individuals are more easily controlled and ultimately brainwashed.