The Absolute Truth covered by māyā is called matter. Matter dovetailed for the cause of the Absolute Truth regains its spiritual quality. Kṛṣṇa consciousness is the process of converting the illusory consciousness into Brahman, or the Supreme. When the mind is fully absorbed in Kṛṣṇa consciousness, it is said to be in samādhi, or trance. Anything done in such transcendental consciousness is called yajṣa, or sacrifice for the Absolute. In that condition of spiritual consciousness, the contributor, the contribution, the consumption, the performer or leader of the performance, and the result or ultimate gain—everything—becomes one in the Absolute, the Supreme Brahman. That is the method of Kṛṣṇa consciousness.
(Bhagavad-Gita----4:24----purport).

A devotee of the Supreme Lord should not worry whether he will depart by arrangement or by accident. The devotee should be firmly established in Kṛṣṇa consciousness and chant Hare Kṛṣṇa. He should know that concern over either of these two paths is troublesome. The best way to be absorbed in Kṛṣṇa consciousness is to be always dovetailed in His service, and this will make one's path to the spiritual kingdom safe, certain and direct. The word yoga-yukta is especially significant in this verse. One who is firm in yoga is constantly engaged in Kṛṣṇa consciousness in all his activities. Śrī Rūpa Gosvāmī advises, anāsaktasya viṣayān yathārham upayuṣjataḥ: one should be unattached in material affairs and do everything in Kṛṣṇa consciousness. By this system, which is called yukta-vairāgya, one attains perfection. Therefore the devotee is not disturbed by these descriptions, because he knows that his passage to the supreme abode is guaranteed by devotional service.
(Bhagavad-Gita----8:27----purport).

The Supersoul gives the individual soul all facilities to achieve whatever he desires to enjoy in this material world. Suffering is a reaction to the living entity's propensity to try to lord it over the material world. But the Lord instructs His friend, the individual soul, who is also His son, to give up all other engagements and simply surrender unto Him for perpetual bliss and an eternal life full of knowledge. This is the last instruction of Bhagavad-gītā, the most authorized and widely read book on all varieties of yoga. Thus the last word of Bhagavad-gītā is the last word in the perfection of yoga. It is stated in Bhagavad-gītā that a person who is always absorbed in Kṛṣṇa consciousness is the topmost yogī.
(Srimad Bhagavatam----3:15:45----purport).

In the Vaikuṇṭha planets there are husbands and wives, but there is no question of their giving birth to children or having sex life. In the Vaikuṇṭha planets both husbands and wives are extraordinarily beautiful, and they are attracted to one another, but they do not enjoy sex life. Indeed, they consider sex not to be very relishable because both husband and wife are always absorbed in Kṛṣṇa consciousness and in glorifying and chanting the glories of the Lord. According to Bhaktivinoda Ṭhākura also, a husband and wife can turn the home into a place as good as Vaikuṇṭha, even while in this material world. Being absorbed in Kṛṣṇa consciousness, even in this world husband and wife can live in Vaikuṇṭha simply by installing the Deity of the Lord within the home and serving the Deity according to the directions of the śāstras. In this way, they will never feel the sex urge. That is the test of advancement in devotional service. One who is advanced in devotional service is never attracted by sex life, and as soon as one becomes detached from sex life and proportionately attached to the service of the Lord, he actually experiences living in the Vaikuṇṭha planets. In the ultimate issue, there is actually no material world, but when one forgets the service of the Lord and engages himself in the service of his senses, he is said to be living in the material world.
(Srimad Bhagavatam----3:23:29----purport).

The activities of the living entity in the body of a dog may be experienced in the mind of a different body; therefore those activities appear never to have been heard or seen. The mind continues, although the body changes. Even in this life-span we can sometimes experience dreams of our childhood. Although such incidents now appear strange, it is to be understood that they are recorded in the mind. Because of this, they become visible in dreams. The transmigration of the soul is caused by the subtle body, which is the storehouse of all kinds of material desires. Unless one is fully absorbed in Kṛṣṇa consciousness, material desires will come and go. That is the nature of the mind—thinking, feeling and willing. As long as the mind is not engaged in meditation on the lotus feet of the Supreme Personality of Godhead, Kṛṣṇa, the mind will desire so many material enjoyments. Sensual images are recorded in the mind in chronological order, and they become manifest one after another; therefore the living entity has to accept one body after another. The mind plans material enjoyment, and the gross body serves as the instrument to realize such desires and plans. The mind is the platform onto which all desires come and go.
(Srimad Bhagavatam----3:29:68----purport).

If we practice Kṛṣṇa consciousness in this present body while in a healthy condition and in good mind, simply by chanting the holy mahā-mantra, Hare Kṛṣṇa, we will have every possibility of fixing the mind upon Kṛṣṇa at the time of death. If we do this, then our lives become successful without any doubt. But if we keep our minds always absorbed in fruitive activities for material enjoyment, then naturally at the time of death we shall think of such activities and again be forced to enter material, conditioned bodies to suffer the threefold miseries of material existence. Therefore, to remain always absorbed in Kṛṣṇa consciousness was the standard of the inhabitants of Vṛndāvana, as exhibited by Mahārāja Nanda, Yaśodā and the gopīs. If we can simply follow in their footsteps, even to a minute proportion, our lives will surely become successful, and we shall enter the spiritual kingdom, Vaikuṇṭha.
(Krsna Book).

It is stated in the Bhagavad-gītā that one who engages all his activities and senses in the devotional service of the Lord becomes completely peaceful because the Supersoul is satisfied with him; thus the devotee becomes transcendental to all dualities, such as heat and cold, honor and dishonor. Being freed from all dualities, he feels transcendental bliss, and he no longer suffers cares and anxieties due to material existence. The Bhagavad-gītā confirms that the devotee always absorbed in Kṛṣṇa consciousness has no anxieties for his maintenance or protection. Being constantly absorbed in Kṛṣṇa consciousness, he ultimately achieves the highest perfection. While in material existence, he lives very peacefully and blissfully, without cares and anxieties, and after quitting this body he goes back home, back to Godhead. The Lord confirms in the Bhagavad-gītā, “My supreme abode is a transcendental place from which, having gone, one never returns to this material world. Anyone who attains the supreme perfection, being engaged in My personal devotional service in the eternal abode, reaches the highest perfection of human life and does not have to come back to the miserable material world.”
(Krsna Book).