What is evil?

This last month, I've had cause to contemplate the nature of evil. What exactly IS evil? Does anybody know anymore? I don't think so.
I actually started my thought process on the flip side of the coin by considering the importance of love. I read how Christ healed a man who was lame on the Sabbath. I wondered why He didn't just wait a day and heal the man then. If He had done that, wouldn't He have satisfied both the letter AND the spirit of the law? And what if the man had been dying, instead of just lame. The point of this story is to ALWAYS put the spirit of the law above the letter of the law. If the man had been dying, the point would have been ONLY consider the spirit of the law if you have no choice.
Okay. Then what is the "spirit" of the law? It is love. So then, I thought further and wondered, "Well, what is love?" Simply put; love is giving. John 3:16 paraphrased and condensed would read, "For God so loved, HE GAVE." Simple.
So what is sin? I believe that sin is anything we say or do, that we do not say or do coming from a place of love. Why is it a sin to steal? Because you are taking. Why is it a sin to covet? Because you want to take. Love is giving. period.
So back to what is evil? Sin is evil. Therefore when we are not coming from a place of love, we are evil. God is love and He is not evil and the flip of that is if WE do not love, we ARE evil.
Now, lets be practical. In this world, and in my experience, when one is truly loving and truly giving, you end up with a lot of knives in your back. And it was a particular knife in my back that started me thinking along these lines.
It is one thing to understand spiritual principles, but quite another to apply them to this world. Perhaps this is our struggle? I don't know, but some days, I wonder, "Whats the point?"