As one sows, so shall one reap. Every effect arises from a cause. Under certain conditions, a cause will come to an effect. This is a universal principle, on which Buddhist morality is based.
Here's a verse.
In the world, some beings are fortunate while others are less fortunate. Some are happy while others are less happy. Why?
The Buddha has specifically stated that Karma explains the differences between living beings. It is also Karma that explains the circumstances that living beings find themselves in.
It is a verse which expresses the Buddhist doctrine of moral determinism.
The situation that anyone experience is the result of his/her past deeds.
Cause and effect have their corresponding relations.
What is Karma?
Karma is not fate nor predestination.
Literally, Karma means "action", "to do".
Action itself is considered neither good nor bad, but only the intention and thought make it so. Thus, Karma is an intentional, conscious, deliberate and wilful action. Karma is volition.
Every action must have a reaction, i.e. an effect. The truth applies both to physical world (expressed by the great physicist Newton) and to the moral world.
Law of Karma is an important application of the Principle of Cause and Effect in morality.
The denial of the Law will destroy all moral responsibility.
There are two kinds of Karma:
For unintentional actions, such as walking, sleeping, breathing, they have no moral consequences, thus constitute neutral Karma or ineffective Karma.
By practicing the Ten Good Deeds and Ten Meritorious Deeds, the fully ripened fruit of these wholesome actions consists of rebirth in the higher realms of happiness, i.e. Man, Asura and Deva.
Conversely, the full ripened fruit of the unwholesome action consists of rebirth in the lower realms of suffering, i.e. Hell, Hungry ghosts and Animals.
The effect of Karma may be evident either in short term or in the long term. Karma can either manifest its effects in this very life or in the next life or only after several lives.
Every cause has its effect. However, there must be conditions that are ripe for the effect. Karma, be it good or bad, can be affected by the conditions under which the actions are performed.
The conditions that determine the strength or weight of Karma apply to the subject and object of the action. Moreover, there are five conditions that modify the strength of Karma:
Though Buddhism stresses on Karma, it rejects fate. One should take good actions all the time, and let all good conditions arise so that: