I don't like the word 'karma' as that is part of a religious belief.
However, I do believe in 'what goes around comes around'.
If people choose to go around doing negative things to others for their own advancement, then eventually all that negativity will bite them in the bum.
I've seen it happen so many times.
These people will be punished and the punishment will be that they have to live the rest of their lives with their crappy selves.
None of us knows what others feel on the inside.
How many people can we think of that appear to 'have it all' yet they bounce from one unsatisfactory situation to another. They go into a downward spiral of drink, drugs, porn, promiscuity, crime in an attempt to find something or lose something.
If you do good, you get what you deserve. That's positive thinking, and do good for your soul.
This ^ is sound advice.