(Krishna tells Arjuna in the Bhagavad-gita that the body is temporary, but the soul is eternal)
"So Bhagavad-gītā begins with this point, that one should know that he is not this material body. That knowledge is lacking at the present moment throughout the whole world. Yes. Everyone is identifying with this body like the animals. Therefore Kṛṣṇa chastised Arjuna that 'You have got animalistic concept of life, and still you're speaking like a very learned scholar. No learned scholar laments on account of this body.' It is said in the Bhagavad-gītā, dhīras tatra na muhyati (BG 2.13). Dhīra... Dhīra means one who is sober by education. He is not disturbed. Just like when a man dies, his relatives lament, cry, 'My father is gone. My father is gone. My father is no more,' or 'My son is no more.' Anyway, they lament like that. But if he is little sober, he can understand, he can study, that I am lamenting, 'My father is gone,' 'My son is gone,' but he's not gone. He's lying on the bed or on the floor. Then why I am speaking 'gone'? If some friend asks him, 'Why you are lamenting, My father is gone, My son is gone? He's lying here,' but still he will say, 'No, he's not. He may be lying there, but he's gone.' That is puzzle. He's lying there and gone? What is this contradiction? That is the point to understand about the soul. The relative is lamenting, crying, 'My father is gone.' That means he never saw his father; he saw the body only. But at the time of death of his father he understands that this father is not this body; that is soul."
(Srila Prabhupada Lecture, Mexico City, February 12, 1975)