The Sanskrit word “karma” comes from a root that means “to do or act.” The law of karma says that people reap what they sow. In essence, the law of karma is a law of justice that implies that every thought or deed, whether good or bad, counts in determining how a person will be born in his next life on Earth.
The idea of karma is that every thought, word, or deed will influence whether individuals achieve liberation or will have to repeat the cycle of birth and death. Karma might be understood as the spiritual or ethical residue of every action; in other words, beyond its external, visible effects, every action has a deep impact on our spiritual relationship.
At the dawn of Indian philosophy, Indians came to believe that every action and every thought had a consequence, which would show up in the present life or in a succeeding one. Most Indian sects believed karma operated as an automatic moral sanction, ensuring the evildoer suffered and the righteous prospered.
A person with bad karma could suffer being reborn many times into lower castes of humans — or even lower animals — and then could not be released until she had been reborn in the Brahmin, or priestly, caste. The doctrine that traces back to the Upanishads maintains that all living creatures are responsible for their karma. To be more specific, they are responsible for their actions and the effects of their actions. They themselves can control their release from the cycle of birth and rebirth.