That you believe or not in Karma doesn’t matter on the power it does have on your life.
If you don’t see the result or influence your actions have, it doesn’t mean it didn’t had any. It just means that you haven’t notice it (yet).
“How people treat you is their karma; how you react is yours.”
- Wayne Dyer
When someone wrong you, it doesn’t give you a free pass to wrong them in return.