Are there any who do evil while truly believing that they do evil?

Don’t those who know their actions are wrong still believe that the rule does not apply to them or to the context of their actions, that a greater good is served by their transgression?

I cannot think of a single instance where I know I have done something our society considers wrong or immoral in which I didn’t believe some other good outweighed the general consensus. Casting my eyes to the actions of others, even the most reviled of criminals, I know of none who truly believed their actions, at the time they committed their crimes, were evil. What do I make of this knowledge; how do I reconcile this universal desire to serve some idea of good with the truth that our actions are quite capable and efficient at harming each other?

There’s a refrain I’ve heard in Christianity many times: “Hate the sin, not the sinner.” Perhaps I can draw some wisdom from that line – that we each act out of some good intention, serving some idea of good, but that certain ideas of goodness pit us against each other, allowing us to harm each other more easily.

There are deeper issues here: I am afraid of my anger and the strength and passion within it. This fear endears me to the teachings of compassion and understanding, but am I simply running still from what needs to happen?