This life is preparation for the next life. You can prepare. It is in your hand. It is in your hand. God has given you the superior intelligence better than the animals. The animals are simply interested eating, sleeping, mating and fearing. So we have got better intelligence, so we must utilize it. Therefore Narottama dāsa Ṭhākura sings, you know, those who are..., the song, hari hari biphale janama goṅāinu: "My Lord, I have simply wasted my life." Why? Manuṣya-janama pāiyā, rādhā-kṛṣṇa na bhajiyā, jāniyā śuniyā viṣa-khāinu: "I got this nice human form of body for understanding, worshiping Rādhā-Kṛṣṇa. Now, I did not do anything. That means knowingly I have taken poison."
So if we misuse this human form of life only like animals, eating, sleeping, sex and fearing, then we are spoiling our life. We must prepare next life. If we don't, then after death we have to go to the Yamarāja, and he will decide what kind of next body. Body will change. Kṛṣṇa says in the Bhagavad, tathā dehāntara-prāptiḥ (BG 2.13). After death you have to change the body. As you are changing from childhood to boyhood, boyhood to youthhood, similarly this old body, when it is no more usable, that means death. But the subtle body, mind, intelligence, that is... We have got proof. At night this body is silent, but your mind, intelligence and ego takes you somewhere. You dream that "I have come to here." Sometimes we dream, "I am flying in the sky," or gone to some forest or some friend's house or so many things, "I am talking with a beautiful girl or beautiful man." So this dream we every day see. So that means when this body stops, the gross body, the subtle body is there. Why don't you believe it? Unless the subtle body is working, how do you dream? The dreaming means subtle body is working. So transmigration of the soul means the soul is twice covered—subtle body and gross body, just like shirt and coat. So when this gross body is finished, the subtle body is there. It takes you to another body. The subtle body with the semina of the father, it is injected in the mother's womb, and then again you will develop another body. This is the process of transmigration.
So this body, how you'll be transferred to another body, that will be judged by the Yamarāja. Daiva-netreṇa. Karmaṇā daiva-netreṇa (SB 3.31.1). By our activities we shall be judged. Those who are criminal, they will be judged, not that everyone will be judged. So..., and because those who are devotees, they are... Mad-yajino 'pi yānti mām (BG 9.25). Those who have devoted their life, dedicated their life only in Kṛṣṇa consciousness, they are sure. Kṛṣṇa says, tyaktvā dehaṁ punar janma naiti mām eti (BG 4.9). That is sure, they are going back to home, back to Godhead. And those who are not dedicated or taken to Kṛṣṇa consciousness, they are criminals. They will be taken to the Yamarāja's court, and Yamarāja will decide what kind of body. There are 8,400,000 different forms of body, and he will be given a certain type of body. This is called transmigration of the soul.