I have this tattooed on my left side! I love the saying and it's a perfect description of Karma, don't judge/discriminate and don't do to someone what you wouldn't want done to you.
We are the makers of our own lives. There is no such thing as fate. Our lives are the result of our previous actions, our karma, and it naturally flows that, having been ourselves the makers of our karma, we must also be able to unmake it.
Unless you see your nature, you shouldn't go around criticizing the goodness of others. There's no advantage in deceiving yourself. Good and bad are distinct. Cause and effect are clear. But fools don't believe and fall straight into a hell of endless darkness without even knowing it. What keeps them from believing is the heaviness of their karma. They're like blind people who don't believe there's such a thing as light. Even if you explain it to them, they still don't believe, because they're blind. How can they possibly distinguish light?
A buddha is someone who finds freedom in good fortune and bad. Such is his power that karma can't hold him. No matter what kind of karma, a buddha transforms it. Heaven and hell are nothing to him. But the awareness of a mortal is dim compared to that of a buddha, who penetrates everything, inside and out.
From the scientific view, the theory of karma may be a metaphysical assumption -- but it is no more so than the assumption that all of life is material and originated out of pure chance
I am the owner of my actions, heir to my actions, born of my actions, related through my actions, and have my actions as my arbitrator. Whatever I do, for good or for evil, to that I will fall heir.
The virtues we acquire, which develop slowly within us, are the invisible links that bind each one of our existences to the others - existences which the spirit alone remembers, for Matter has no memory for spiritual things.