Different religions call it different names, but it's found in all of them.. the idea that ultimately the deficit between what struggles you face and what rewards you are given are balanced. There's an old Russian story of a woman thar faced judgment on her life and didn't look good for her. But, then they took into account the struggles she faced in life, and she was cleared. But, it's not always end of days that we see it but in this life, too.
Taylor Swift sings that Karma is her boyfriend. Well, the sports player boyfriend isn't named Katma, but you get the point. Her life definitely is more rewarded than the decades she clawed her way up. In my case, it would be girlfriend, and like her I'd say that the idea gives me comfort to know my deficit will be reconciled, even as the idea of Karma must scare those that misused me. Indeed, without my intervention or even will, I can look at those individuals lives and see that they faced the penalty in their lives ... the deeper the bettayal.. the harsher the result. All that is left is the positive addition to my life for what I gave.
But, this is where it is important to be objective about the good and bad in our lives. Not all that we call bad is bad, and not all we call good is good. It's like those that call themselves rich but are living on credit cards. I saw a study once that over half of those that were middle to upper class were living on credit and debt and in reality were broke... much like Inventing Anna show on Netflix that is based on a true story. But, people want what they see, even if what they see is a lie, too.
Similarly, the accepted perception is that it is better and happier to be in a relationship and less so to be single. That CAN be true, but it can also be a similar illusion. Not all that are in a relationship is happy and not all single are sad. There are benefits to being single that make you happy, too. So, you have to temper Karma with the realization that you may be receiving your reward in other ways, even now.
That said... my life is definitely in deficit of what I've given, and like weather patterns that revolve around and operate to balance low pressure areas, I look forward to seeing the storms of reward that arrive this year.