Bhagavad Gita 3.4न कर्मणामनारम्भान्नैष्कर्म्यं पुरुषोऽश्नुते।न च संन्यसनादेव सिद्धिं समधिगच्छति ॥

Actionlessness (Naishkarmyam) and perfection (Siddhi) are synonymous. The sage who has attained to perfection or reached the state of actionlessness rests in his own essential nature as ExistenceKnowledgeBliss Absolute (Satchidananda Svarupa). He has neither necessity nor desire for action as a means to an end. He has perfect satisfaction in the Self.One attains to the state of actionlessness by gaining the knowledge of the Self. If a man simply sits quiet by abandoning action you cannot say that he has attained to the state of actionlessness. His mind will be planning, scheming and speculating. Thought is real action. The sage who is free from affirmative thoughts, wishes, and likes and dislikes, who has the knowledge of the Self can be said to have attained to the state of actionlessness.No one can reach perfection or freedom from action or knowledge of the Self by mere renunciation or by simply giving up activities without possessing the knowledge of the Self. (Cf.XVIII.49).