The process of quitting this body and getting another body in the material world is also organized. A man dies after it has been decided what form of body he will have in the next life. Higher authorities, not the living entity himself, make this decision. According to our activities in this life, we either rise or sink. This life is a preparation for the next life. If we can prepare, therefore, in this life to get promotion to the kingdom of God, then surely, after quitting this material body, we will attain a spiritual body just like the Lord's.
(Bhagavad-Gita---introduction).

A demoniac person, being always against God's supremacy, does not like to believe in the scriptures. He is envious of both the scriptures and the existence of the Supreme Personality of Godhead. This is caused by his so-called prestige and his accumulation of wealth and strength. He does not know that the present life is a preparation for the next life. Not knowing this, he is actually envious of his own self, as well as of others. He commits violence on other bodies and on his own. He does not care for the supreme control of the Personality of Godhead, because he has no knowledge. Being envious of the scriptures and the Supreme Personality of Godhead, he puts forward false arguments against the existence of God and denies the scriptural authority. He thinks himself independent and powerful in every action. He thinks that since no one can equal him in strength, power or wealth, he can act in any way and no one can stop him. If he has an enemy who might check the advancement of his sensual activities, he makes plans to cut him down by his own power.
(Bhagavad-Gita----16:18----purport).

The foolishness of gross materialism is that people think of making a permanent settlement in this world, although it is a settled fact that one has to give up everything here that has been created by valuable human energy. Great statesmen, scientists, philosophers, etc., who are foolish, without any information of the spirit soul, think that this life of a few years only is all in all and that there is nothing more after death. This poor fund of knowledge, even in the so-called learned circles of the world, is killing the vitality of human energy, and the awful result is being keenly felt. And yet the foolish materialistic men do not care about what is going to happen in the next life. The preliminary instruction in the Bhagavad-gītā is that one should know that the identity of the individual living entity is not lost even after the end of this present body, which is nothing but an outward dress only. As one changes an old garment, so the individual living being also changes his body, and this change of body is called death. Death is therefore a process of changing the body at the end of the duration of the present life. An intelligent person must be prepared for this and must try to have the best type of body in the next life. The best type of body is a spiritual body, which is obtained by those who go back to the kingdom of God or enter the realm of Brahman. In the second chapter of this canto, this matter will be broadly discussed, but as far as the change of body is concerned, one must prepare now for the next life.
(Srimad Bhagavatam----2:1:15----purport).

To prepare oneself for the better next life, one must get out of one's so-called home. The system of varṇāśrama-dharma, or sanātana-dharma, prescribes retirement from family encumbrances as early as possible after one has passed fifty years of age. Modern civilization is based on family comforts, the highest standard of amenities, and therefore after retirement everyone expects to live a very comfortable life in a well-furnished home decorated with fine ladies and children, without any desire to get out of such a comfortable home. High government officers and ministers stick to their prize posts until death, and they neither dream nor desire to get out of homely comforts. Bound by such hallucinations, materialistic men prepare various plans for a still more comfortable life, but suddenly cruel death comes without mercy and takes away the great planmaker against his desire, forcing him to give up the present body for another body. Such a planmaker is thus forced to accept another body in one of the 8,400,000 species of life according to the fruits of the work he has performed. In the next life, persons who are too much attached to family comforts are generally awarded lower species of life on account of sinful acts performed during a long duration of sinful life, and thus all the energy of the human life is spoiled.
(Srimad Bhagavatam----2:1:16----purport).

In order to be saved from the danger of spoiling the human form of life and being attached to unreal things, one must take warning of death at the age of fifty, if not earlier. The principle is that one should take it for granted that the death warning is already there, even prior to the attainment of fifty years of age, and thus at any stage of life one shouldprepare himself for a better next life. The system of the sanātana-dharma institution is so made that the follower is trained for the better next life without any chance that the human life will be spoiled. The holy places all over the world are meant for the residential purposes of retired persons getting ready for a better next life. Intelligent persons must go there at the end of life, and for that matter, after fifty years of age, to live a life of spiritual regeneration for the sake of being freed from family attachment, which is considered to be the shackle of material life. One is recommended to quit home just to get rid of material attachment because one who sticks to family life until death cannot get rid of material attachment and as long as one is materially attached one cannot understand spiritual freedom. One should not, however, become self-complacent simply by leaving home or by creating another home at the holy place, either lawfully or unlawfully. Many persons leave home and go to such holy places, but due to bad association, again become family men by illicit connection with the opposite sex. The illusory energy of matter is so strong that one is apt to be under such illusion at every stage of life, even after quitting one's happy home. Therefore, it is essential that one practice self-control by celibacy without the least desire for sex indulgence. For a man desiring to improve the condition of his existence, sex indulgence is considered suicidal, or even worse. Therefore, to live apart from family life means to become self-controlled in regard to all sense desires, especially sex desires. The method is that one should have a duly sanctified sitting place made of straw, deerskin and carpet, and thus sitting on it one should chant the holy name of the Lord without offense, as prescribed above. The whole process is to drag the mind from material engagements and fix it on the lotus feet of the Lord. This simple process alone will help one advance to the highest stage of spiritual success.
(Srimad Bhagavatam----2:1:16----purport).

The peculiarity of the gradual development of the different senses is simultaneously supported by their controlling deities. It is to be understood, therefore, that the activities of the sense organs are controlled by the will of the Supreme. The senses are, so to speak, offering a license for the conditioned souls, who are to use them properly under the control of the controlling deity deputed by the Supreme Lord. One who violates such controlling regulations has to be punished by degradation to a lower status of life. Consider, for example, the tongue and its controlling deity, Varuṇa. The tongue is meant for eating, and men, animals and birds each have their different tastes because of different licenses. The taste of human beings and that of the swine are not on the same level. The controlling deity, however, awards or certifies a particular type of body when the particular living entity develops a taste in terms of different modes of nature. If the human being develops taste without discrimination, as does the swine, then the controlling deity is certainly certified for the next term to award him the body of a swine. The swine accepts any kind of foodstuff, including stools, and a human being who has developed such indiscriminate taste must be prepared for a degraded life in the next life. Such a life is also God's grace because the conditioned soul desired a body like that for perfectly tasting a particular type of foodstuff. If a man gets the body of a swine it must be considered the grace of the Lord because the Lord awards the facility. After death the next body is offered by superior control, not blindly. A human being, therefore, must be on his guard as to what sort of body he is going to have in the next life. An irresponsible life of indiscrimination is risky, and that is the declaration of all scriptures.
(Srimad Bhagavatam----2:10:19----purport).

How liberation is imperceptibly achieved by a pure devotee and what the symptoms are have been explained. For the conditioned soul there are two statuses of living. One status is in this present life, and the other is our preparation for the next life. If I am in the mode of goodness then I may be preparing for promotion to the higher planets, if I am in the mode of passion then I shall remain here in a society where activity is very prominent, and if I am in the mode of ignorance I may be degraded to animal life or a lower grade of human life. But for a devotee there is no concern for this life or the next life because in any life he does not desire elevation in material prosperity or a high-grade or low-grade life. He prays to the Lord, "My dear Lord, it does not matter where I am born, but let me be born, even as an ant, in the house of a devotee." A pure devotee does not pray to the Lord for liberation from this material bondage. Actually, the pure devotee never thinks that he is fit for liberation. Considering his past life and his mischievous activities, he thinks that he is fit to be sent to the lowest region of hell. If in this life I am trying to become a devotee, this does not mean that in my many past lives I was one-hundred-percent pious. That is not possible. A devotee, therefore, is always conscious of his real position. Only by his full surrender to the Lord, by the Lord's grace, are his sufferings made shorter. As stated in Bhagavad-gītā, "Surrender unto Me, and I will give you protection from all kinds of sinful reaction." That is His mercy. But this does not mean that one who has surrendered to the lotus feet of the Lord has committed no misdeeds in his past life. A devotee always prays, "For my misdeeds, may I be born again and again, but my only prayer is that I may not forget Your service." The devotee has that much mental strength, and he prays to the Lord: "May I be born again and again, but let me be born in the home of Your pure devotee so that I may again get a chance to develop myself."
(Srimad Bhagavatam----3:25:39-40----purport).

After birth the child may forget about the difficulties of his past lives, but when we are grown-up we can at least understand the grievous tortures undergone at birth and death by reading the authorized scriptures like Śrīmad-Bhāgavatam. If we do not believe in the scriptures, that is a different question, but if we have faith in the authority of such descriptions, then we must prepare for our freedom in the next life; that is possible in this human form of life. One who does not take heed of these indications of suffering in human existence is said to be undoubtedly committing suicide. It is said that this human form of life is the only means for crossing over the nescience of māyā, or material existence. We have a very efficient boat in this human form of body, and there is a very expert captain, the spiritual master; the scriptural injunctions are like favorable winds. If we do not cross over the ocean of the nescience of material existence in spite of all these facilities, then certainly we are all intentionally committing suicide.
(Srimad Bhagavatam----3:31:9----purport).

An advanced devotee, or a perfect human being who is actually wise and learned, cannot give up his service at the lotus feet of the Lord. Although Lord Brahmā has a long life-span (4,320,000,000 years constitute twelve hours in a day of Brahmā), Brahmā is afraid of death and consequently engages in the devotional service of the Lord. Similarly, all the Manus who appear and disappear during the day of Brahmā are also engaged in the Lord's devotional service. In Brahmā's one day, fourteen Manus appear and disappear. The first Manu is Svāyambhuva Manu. Each Manu lives for seventy-one yugas, each consisting of some 4,320,000 years. Although the Manus have such a long life-span, they still prepare for the next life by engaging in the devotional service of the Lord. In this age human beings only live for sixty or eighty years, and even this small life-span is gradually decreasing. Therefore it is even more imperative for human beings to take to the worship of the lotus feet of the Lord by constantly chanting the Hare Kṛṣṇa mantra, as recommended by Lord Caitanya Mahāprabhu.
(Srimad Bhagavatam----4:24:67----purport).

Materialistic life means forgetting one's constitutional position as the eternal servant of Kṛṣṇa, and this forgetfulness is especially enhanced in the gṛhastha-āśrama. In the gṛhastha-āśrama a young man accepts a young wife who is very beautiful in the beginning, but in due course of time, after giving birth to many children and becoming older and older, she demands many things from the husband to maintain the entire family. At such a time the wife becomes detestable to the very man who accepted her in her younger days. One becomes attached to the gṛhastha-āśrama for two reasons only—the wife cooks palatable dishes for the satisfaction of her husband's tongue, and she gives him sexual pleasure at night. A person attached to the gṛhastha-āśrama is always thinking of these two things—palatable food and sex enjoyment. The talks of the wife, which are enjoyed as a family recreation, and the talks of the children both attract the living entity. He thus forgets that he has to die someday and has to prepare for the next life if he wants to be put into a congenial body.
The deer in the flower garden is an allegory used by the great sage Nārada to point out to the King that the King himself is similarly entrapped by such surroundings. Actually everyone is surrounded by such a family life, which misleads one. The living entity thus forgets that he has to return home, back to Godhead. He simply becomes entangled in family life. Prahlāda Mahārāja has therefore hinted: hitvātma-pātaṁ gṛham andha-kūpaṁ vanaṁ gato yad dharim āśrayeta (S.B.7:5:5). Family life is considered a blind well (andha-kūpam) into which a person falls and dies without help. Prahlāda Mahārāja recommends that while one's senses are there and one is strong enough, he should abandon the gṛhastha-āśrama and take shelter of the lotus feet of the Lord, going to the forest of Vṛndāvana. According to Vedic civilization, one has to give up family life at a certain age (the age of fifty), take vānaprastha and eventually remain alone as a sannyāsī. That is the prescribed method of Vedic civilization known as varṇāśrama-dharma. When one takes sannyāsa after enjoying family life, he pleases the Supreme Lord Viṣṇu.
One has to understand one's position in family or worldly life. That is called intelligence. One should not remain always trapped in family life to satisfy his tongue and genitals in association with a wife. In such a way, one simply spoils his life. According to Vedic civilization, it is imperative to give up the family at a certain stage, by force if necessary. Unfortunately, so-called followers of Vedic life do not give up their family even at the end of life, unless they are forced by death. There should be a thorough overhauling of the social system, and society should revert to the Vedic principles, that is, the four varṇas and the four āśramas.
(Srimad Bhagavatam----4:29:54----purport).

In this life we have to prepare ourselves for promotion to the next life. Those who are in the mode of rajo-guṇa are generally interested in being promoted to the heavenly planets. Some, unknowingly, are degraded to lower animal forms. Those in the mode of goodness can engage in devotional service, and after that they can return home, back to Godhead (yānti mad-yājino 'pi mām). That is the real purpose of human life. This Kṛṣṇa consciousness movement is trying to bring intelligent human beings to the platform of devotional service. Instead of wasting time trying to attain a better position in material life, one should simply endeavor to return home, back to Godhead. Then all problems will be solved.
(Srimad Bhagavatam----5:14:31----purport).

Unfortunately, people in general do not know what is to take place in the next life. To prepare oneself for his next life is common sense, and it is a principle of the Vedic civilization, but presently people throughout the world do not believe in a next life. Even influential professors and other educators say that as soon as the body is finished, everything is finished. This atheistic philosophy is killing human civilization. People are irresponsibly performing all sorts of sinful activities, and thus the privilege of the human life is being taken away by the educational propaganda of the so-called leaders. Actually it is a fact that this life is meant for preparation for the next life; by evolution one has come through many species, or forms, and this human form of life is an opportunity to promote oneself to a better life.
(Sri Caitanya Caritamrta----1:9:43----purport).

This is a solution to all sinful activities. In this Age of Kali everyone is perplexed by so many inconveniences—social, political and religious—and naturally no one is happy. Due to the contamination of this age, everyone has a very short life. There are many fools and rascals who advise people to adopt this way of life or that way of life, but real liberation from life's perplexities means preparation for the next life. Tathā dehāntara-prāptir dhīras tatra na muhyati (B.G.2:13). One should be situated in his spiritual identity and return home, back to Godhead. The simplest method for this is recommended herein by Śrī Caitanya Mahāprabhu. We should constantly chant the holy names of the Lord, the Hare Kṛṣṇa mahā-mantra. Following in the footsteps of Śrī Caitanya Mahāprabhu, the Kṛṣṇa consciousness movement is recommending this process all over the world. We are saying, "Chant the Hare Kṛṣṇa mahā-mantra, be freed from all the complexities of life, and realize Kṛṣṇa, the Supreme Personality of Godhead. Engage in His devotional service and perfect your life so that you can return home, back to Godhead."
(Sri Caitanya Caritamrta----2:25:198----purport).

Bhakti-rasa, however, the mellow relished in the transcendental loving service of the Lord, does not finish with the end of life. It continues perpetually and is therefore called amṛta, that which does not die but exists eternally. This is confirmed in all Vedic literatures. Bhagavad-gītā says that a little advancement in bhakti-rasa can save the devotee from the greatest danger—that of missing the opportunity for human life. The rasas derived from our feelings in social life, in family life or in the greater family life of altruism, philanthropy, nationalism, socialism, communism, etc., do not guarantee that one's next life will be as a human being. We prepare our next life by our actual activities in the present life. A living entity is offered a particular type of body as a result of his action in the present body. These activities are taken into account by a superior authority known as daiva, or the authority of God. This daiva is explained in Bhagavad-gītā as the prime cause of everything, and in Śrīmad-Bhāgavatam it is stated that a man takes his next body by daiva-netreṇa, which means by the supervision of the authority of the Supreme. In an ordinary sense, daiva is explained as destiny. Daiva supervision gives us a body selected from 8,400,000 forms; the choice does not depend on our selection, but is awarded to us according to our destiny. If our body at present is engaged in the activities of Kṛṣṇa consciousness, then it is guaranteed that we will have at least a human body in our next life. A human being engaged in Kṛṣṇa consciousness, even if unable to complete the course of bhakti-yoga, takes birth in the higher divisions of human society so that he can automatically further his advancement in Kṛṣṇa consciousness. Therefore, all bona fide activities in Kṛṣṇa consciousness are amṛta, or permanent.
(Nectar of Devotion).

Śukadeva Gosvāmī, after citing the example of Mahārāja Khaṭvāṅga, who prepared himself for the next life within a very short time, encouraged Mahārāja Parīkṣit by saying that since he still had seven days at his disposal, he could easily take advantage of the time to prepare himself for the next life. Indirectly, the Gosvāmī told Mahārāja Parīkṣit that be should take shelter of the sound representation of the Lord for the seven days still remaining in the duration of his life and thus get himself liberated. In other words, everyone can best prepare himself for the next life simply by hearing Śrīmad-Bhāgavatam, as it was recited by Śukadeva Gosvāmī to Mahārāja Parīkṣit. The rituals are not formal, but there are also some favorable conditions, which are required to be carried out, as instructed hereafter.
(Srimad Bhagavatam----2:1:14----purport).