Therefore in this human life, if we do not purify our existence, then we go on with this impure existence. Impure existence means transmigration of the soul from one body to another, and become subjected to birth, death, old age and disease. This is impurification. So they do not know that "Death is not my obligation. Because I am impure, therefore I am dying. Birth is not my obligation. Because I am impure, therefore I am taking birth." Janma-mṛtyu... Four things: janma-mṛtyu-jarā-vyādhi (BG 13.9). Janma, birth, is due to my impure consciousness. Therefore if we purify our consciousness by advancing, by developing Kṛṣṇa consciousness, then we become pure. This is the process of Kṛṣṇa consciousness movement. Ceto-darpaṇa-mārjanam (CC Antya 20.12), Caitanya Mahāprabhu says, cleansing the heart. And all these purificatory methods, they are based on cleansing the heart. If I think myself that "I am something of this material product..." The scientists, they say that "I am these material things." They do not understand what is spiritual identity. And I do, I act, according to that material conception, that is impurity of my consciousness. First thing is to understand that "I am not this material body."
Impure existence means