Nishiddhakarma (means prohibited actions) refers to actions that are to be avoided by an aspirant. Nishiddhakarmas are actions expressly prohibited by Vedic or other scriptural injunctions. It comprises any karma that hinders spiritual progress. God-realization is the real goal of a spiritual path and therefore a sadhaka (devotee practitioner) or upasaka (worshiper) must avoid all prohibited actions. They are termed as adharma.
These forbidden actions are – theft, adultery, falsehood, deception, fraud, oppression, violence, and consuming interdicted food. These actions are prohibited because they render the mind impure and lead to births with unhelpful impressions. Desire for honor, fame, social prestige, wife, progeny, wealth and other transient objects are also regarded as an obstacle and should also be given up.
The mind is the most important instrument. Whatever we know, from the sense object to the highest spirituality, we know only through the mind. Eradication of all desires, greed and attachments from the mind is surely an uphill task. It requires vigor, eagerness and limitless perseverance.
The forbidden karmas upset and disturb the mind, which is the main and important instrument for realizing the Self. It must therefore be kept in a state of equilibrium through self-control. Without purification, no one can control the mind and meditate upon the atman. Through deep meditation alone will the mind become completely absorbed in God, be tranquil and transparent and suffuse with the light of divinity. Such absorption in God is the way for self-realization.