Treat others the way you want to be treated.
This is an oldie but goody, but always true.
Whether you believe in God and reaping what you sow or karma or what have you - it's important to treat other people well.
The key is to treat people the way you want to be treated - not necessarily the way you think they deserve to be treated.
That means being understanding that people make mistakes.
Accepting that people are not perfect.
Allowing people to receive forgiveness if they are genuinely repentant.
It also means being more patient, loving, steadfast, loyal and even-tempered than you normally would be.
After all - you'd like to be treated with patience, love, steadfastness, loyalty and even-temperedness, wouldn't you?
Treat others the way you wanted to be treated. If you put positivity out there in the universe, you will receive that same positivity back. Not necessarily immediately or exactly the way you want it, but you will definitely receive it back. So start sowing positivity by treating others in a kind manner today.