The way to a peaceful mind through yoga

You have grieved for those who deserve no grief, and you talk words of wisdom. Learned men grieve not for the living nor the dead. Never did I not exist, nor you, nor these rulers of men; nor will any one of us ever hereafter cease to be. As in this body, infancy and youth and old age come to the embodied self, so does the acquisition of another body; a sensible man is not deceived about that. The contacts of the senses, Arjuna, which produce cold and heat, pleasure and pain, are not permanent, they are ever coming and going. Bear them, O descendant of Bharata! For, chief of men, that sensible man who is not afflicted by pain or heat, he merits immortality. There is no existence for that which is unreal; there is no non-existence for that which is real. And the correct conclusion about both is perceived by those who perceive the truth. Know that to be indestructible which pervades all this; the destruction of that inexhaustible principle none can bring about. These bodies that pertain to the embodied self which is eternal, indestructible, and indefinable, are said to be perishable; therefore do engage in battle, O descendant of Bharata! He who thinks it to be the killer and he who thinks it to be killed, both know nothing. The self kills not, and the self is not killed. It is not born, nor does it ever die, nor, having existed, does it exist no more. Unborn, everlasting, unchangeable, and primeval, the self is not killed when the body is killed.

- Bhagavad Gita