Swami Vivekananda's Gist of the Gita

In order to remove this delusion which had overtaken Arjuna, what did the Bhagavân say? As I always preach that you should not decry a man by calling him a sinner, but that you should draw his attention to the omnipotent power that is in him, in the same way does the Bhagavan speak to Arjuna. नैतत्त्वय्युपपद्यते — "It doth not befit thee!" "Thou art Atman imperishable, beyond all evil. Having forgotten thy real nature, thou hast, by thinking thyself a sinner, as one afflicted with bodily evils and mental grief, thou hast made thyself so — this doth not befit thee!" — so says the Bhagavan: क्लैब्यं मा स्म गमः पार्थ — Yield not to unmanliness, O son of Pritha. There is in the world neither sin nor misery, neither disease nor grief; if there is anything in the world which can be called sin, it is this — 'fear'; know that any work which brings out the latent power in thee is Punya (virtue); and that which makes thy body and mind weak is, verily, sin. Shake off this weakness, this faintheartedness! क्लैब्यं मा स्म गमः पार्थ। —Thou art a hero, a Vira; this is unbecoming of thee."

If you, my sons, can proclaim this message to the world — क्लैब्यं मा स्म गमः पार्थ नैतत्त्वय्युपपद्यते — then all this disease, grief, sin, and sorrow will vanish from off the face of the earth in three days. All these ideas of weakness will benowhere. Now it is everywhere — this current of the vibration of fear. Reverse the current: bring in the opposite vibration, and behold the magic transformation! Thou art omnipotent — go, go to the mouth of the cannon, fear not.

Hate not the most abject sinner, fool; not to his exterior. Turn thy gaze inward, where resides the Paramâtman. Proclaim to the whole world with trumpet voice, "There is no sin in thee, there is no misery in thee; thou art the reservoir of omnipotent power. Arise, awake, and manifest the Divinity within!"

If one reads this one Shloka — क्लैब्यं मा स्म गमः पार्थ नैतत्त्वय्युपपद्यते । क्षुद्रं हृदयदौर्बल्यं त्यक्त्वोत्तिष्ठ परंतप॥ — one gets all the merits of reading the entire Gita; for in this one Shloka lies imbedded the whole Message of the Gita.