A central tenet of Sanatan Dharma is the law of Karma, or the law of cause and effect. Whenever an action is performed (a cause), there must be an associated effect that is coupled with the action. Good actions bring good effects i.e. pleasure, while bad actions bring bad effects i.e. pain. Behind every action is the seed of desire. This desire prompts thought, which then manifests as action to realise the objects of the desire. The action in actuality has three effects – it produces the appropriate reward based on the type of action (good or bad), it leaves an impression in the mind and it produces an effect in the world.
Actions are like seeds that are planted. Planting one variety of seed only produces a particular type of fruit. For example, planting an apple seed produces an apple tree. Planting an apple seed cannot produce a mango tree. In a similar fashion, actions are tightly coupled with their effects. Virtuous actions lead to positive outcomes, while evil actions lead to pain and suffering.
There are three types of karma – Sanchit Karma, Prarabdha Karma and Agami Karma. Sanchit Karma is stored-up karma that was performed in the past. Not all actions that are performed bring immediate effects. Instead, the effects take some time to materialise. The portion of Sanchit Karma that is currently bearing fruit is known as Prarabdha Karma. Our present circumstances, whether good or bad, is based on this type of karma. Our current actions that are being performed are collectively known as Agami Karma. The portion of these actions which do not have an immediate effect will become Sanchit Karma.
An analogy is given in the Scriptures to make the distinctions between the different types of karmas clearer. Imagine an archer with a quiver full of arrows and a bow. He takes an arrow from the quiver and shoots it. He takes another arrow and prepares to shoot for a second time. The set of arrows in his quiver could be compared to Sanchit Karma or stored-up karma. The first arrow that was shot is likened to Prarabdha Karma i.e. it has already left him and places him in his current situation. The second arrow that he is about to shoot is likened to Agami Karma. He has control over where and how he will shoot it.
In the Bhagavad Gita, Shri Krishna told Arjuna that we are entitled to our actions, but not to the fruits. In other words, we can gain control over our circumstances by understanding that our actions come with pre-determined consequences. If we perform the right type of actions including our duty and service to society with the right attitude, then our circumstance would only be positive. Further, in order to escape from the shackles of karma, it is recommended that we perform actions selflessly i.e. without a sense of doership. This attitude requires that we adopt an attitude where we are merely instruments of the Lord, and all our actions will be solely a manifestation of his will.
In summary, the law of karma implies that we are all masters of our own fate. By our actions, we determined our present circumstances. And by our actions, we can change it. Understanding this important principle, we can take action from this present moment to change our circumstances for the better. All that is required is that we follow scriptural injunctions and avoid scriptural prohibitions.