Karma is action created by physical movement, speech and thought. Each of these "actions" is aligned with a particular energy or vibration - negative or positive, dark or light. The more positive actions we manifest, the higher vibration we create in our lives, and the more our future will unfold in a positive way. On the other hand, the more negative actions we create, the more negativity will unfold in our future. Positive actions are any movements, words or thoughts that come from a place of love, joy, and peace. Negative actions are any movements, words or thoughts that stem from anger, sorrow, or guilt. In Eastern philosophy, karma is carried from lifetime to lifetime. So in previous lifetimes, if we created a lot of negativity, that negativity would manifest in this lifetime. And the same for positivity. So indeed, we can say that our being is a composite of ALL our karma from this lifetime and the eons before.
Now as a man is like this or like that,
according as he acts and according as he behaves, so will he be;
a man of good acts will become good, a man of bad acts, bad;
he becomes pure by pure deeds, bad by bad deeds;
And here they say that a person consists of desires,
and as is his desire, so is his will;
and as is his will, so is his deed;
and whatever deed he does, that he will reap.
— Brihadaranyaka Upanishad, 7th Century BCE
How can we improve our lives through this philosophy? Clearly we must consider how to transform all of our negative karma into positive karma, including our physical action, vocal action, and mental action. Then our entire life becomes an expression of goodness, also known in ancient Vedic tradition as "sattva." "Sattva" is the expression of pure love, peace, joy, and purity. Every deed, word, and thought stems from perfect goodness. In a "sattvic state," the human enters a realm of deep meditation in which the whole world is experienced to be perfect as it is; i.e. total acceptance.
Perhaps the most difficult karma to transform is thought or intention. What motivations do we act from? Even when we say good things or do good things, we often come from a place of selfish motivation. For instance, we might help someone out of guilt or we might represent a good cause out of anger. In other words, the action may be good, but the motivation is impure. Is it possible to act purely for the sake of goodness? Love for love's sake without any conditions? Spiritual practices such as mantra, mudra, and asana can be very helpful in purifying the mind's hidden agenda. When the mind is healed, we become more sattvic, and our negative karma becomes positive karma. Happiness dawns in the mind. We no longer feel the need to change the world because our inner world is radiant.