Gita Chapter Two 02

Verses 2.11 – 2.30
Mourning for what is not worthy of grief is unwise. Those who are wise lament neither for the living nor the dead. Never was there a time when any person - whether,I, you, the kings or any being did not exist. Nor, in the future shall any one among them or us ceased to exist. As the embodied soul continuously passes, in this body, from boyhood to youth to old age, the soul in each body similarly passes into another body at death. A self-realized soul is not bewildered by such a change or transformation. The nonpermanent appearance and disappearance of happiness and distress are like the appearance and disappearance of winter and summer seasons. These are the delusions created by sense perception and the wise learn to tolerate them without losing their stability of peace in mind.disturbed. The person undisturbed by happiness and distress and in steady state under both situations is certainly eligible for liberation. By studying in depth, the seers have concluded that the non-existent cannot endure and the existent cannot cease to be. That which pervades the entire body is indestructible: the imperishable soul cannot be destroyed by anybody or anything. Only the material body of the indestructible, immeasurable and eternal living entity is subject to destruction.
The thought that a living entity is the slayer or one can slay a living entity is flawed and based on ignorance: the person with knowledge knows that the self or the soul slays not nor is slain. The soul is never born, never dies and unborn, eternal, ever existing and primeval. The self lasts even if the body is slain. A learned person who knows that the soul is indestructible, unborn, eternal and immutable, can not think that one can kill anyone or cause anyone to kill. As a person puts on new garments, giving up old ones, similarly, the soul accepts new material bodies, giving up the old and useless ones. The soul can never be cut into pieces by any weapon, nor can he be burned by fire, nor moistened by water, nor withered by the wind. The soul is unbreakable and insoluble, and can be neither burned nor dried. The soul is everlasting, all-pervading, unchangeable, immovable and eternally the same. The soul is invisible, inconceivable, immutable, and unchangeable. Knowing this, one should not grieve for the loss of the body.
Should one think that the soul is born and dies, there is no reason to grieve: for, one who has taken birth, death is certain and for one who is dead, birth is certain. All created beings are non-manifest in the beginning, non-manifest state for sometime state and transformed non-manifest again. So, there is no reason to lament on death. Some know that the soul is amazing but most do not know or understand the nature of the soul at all. The soul that dwells in the body is eternal and can never be slain. Therefore there is no need to grieve for any creature.

Verses 2.31 - 2.39
One belonging to the warrior class (ksatriya) has the specific duty to fight wars and Arjuna therefore should have no hesitation in taking up the unsought opportunity to participate in the battle. If Arjuna does not fight the war, he will neglecting his duties and lose your reputation as a fighter. For an honorable person such disrespect is worse than death. The great generals who have highly esteemed Arjuna will now think of him as a coward who left the battlefield out of fear only. In a battle there are two possibilities: either one earns the distinction of a hero giving up life fighting or a conqueror that wins the kingdom. Arjuna should therefore get up to fight with determination, without worrying about the outcome like happiness or distress, loss or gain, victory or defeat resulting from his action to fight. This is the wisdom derived from the analytical knowledge of Sankhya philosophy or Gyana Yoga.