In other words, if the living entity adulterates his consciousness with the qualities of cats and dogs, in his next life he gets a cat or dog body and enjoys. Consciousness is originally pure, like water. But if we mix water with a certain color, it changes. Similarly, consciousness is pure, for the spirit soul is pure. But consciousness is changed according to the association of the material qualities. Real consciousness is Kṛṣṇa consciousness. When, therefore, one is situated in Kṛṣṇa consciousness, he is in his pure life. But if his consciousness is adulterated by some type of material mentality, in the next life he gets a corresponding body. He does not necessarily get a human body again; he can get the body of a cat, dog, hog, demigod or one of many other forms, for there are 8,400,000 species.
(Bhagavad-Gita-----15:9-----purport).

Devahūti very intelligently says, "One may theoretically analyze and say that by knowledge he has become freed, but actually, as long as the cause exists, he is not free." Bhagavad-gītā confirms that after performing such speculative activities for many, many births, when one actually comes to his real consciousness and surrenders unto the Supreme Lord, Kṛṣṇa, then the fulfillment of his research in knowledge is actually achieved.
(Srimad Bhagavatam-----3:27:20-----purport).

When one's mind and senses are attracted to sense objects for enjoyment, the mind becomes agitated. As a result of continually thinking of sense objects, one's real consciousness almost becomes lost, like the water in a lake that is gradually sucked up by the big grass straws on its bank.
(Srimad Bhagavatam-----3:22:30-----translation).

One should not indulge in eating food in the modes of passion and ignorance. This is called ucitāhāra, or appropriate eating. One who is always eating meat or drinking liquor, which is eating and drinking in passion and ignorance, must give these things up so that his real consciousness may be awakened. In this way one may become peaceful and refreshed. If one is restless or fatigued, one cannot understand the science of God.
(Srimad Bhagavatam-----3:26:11-----purport).

Diseased and conditioned, the living entity transmigrates throughout the universe. Sometimes he is situated in the upper planetary system and sometimes in the lower system. In this way he leads his diseased life. His disease can be cured only when he meets and follows the expert physician, the bona fide spiritual master. When the conditioned soul faithfully follows the instructions of a bona fide spiritual master, his material disease is cured, he is promoted to the liberated stage, and he again attains to the devotional service of Kṛṣṇa and goes back home, back to Kṛṣṇa. A conditioned living entity should become aware of his real position and should pray to the Lord, "How much longer will I be under the rule of all these bodily functions such as lust and anger?" As masters of the conditioned soul, lust and anger are never merciful. Indeed the conditioned soul will never cease rendering service to such bad masters. However, when he comes to his real consciousness, or Kṛṣṇa consciousness, he abandons these bad masters and approaches Kṛṣṇa with a frank and open heart to achieve His shelter. At such a time he prays to Kṛṣṇa to be engaged in His transcendental loving service.
(Teachings of Lord Caitanya).

One who is able to withdraw his senses from sense objects, as the tortoise draws its limbs within the shell, is firmly fixed in perfect consciousness.
(Bhagavad-Gita-----2:58-----translation).

In order to encourage the king, who had only seven remaining days of life, Śrīla Śukadeva Gosvāmī asserted that there is no use in living hundreds of years without any knowledge of the problems of life—better to live for a moment with full consciousness of the supreme interest to be fulfilled. The supreme interest of life is eternal, with full knowledge and bliss. Those who are bewildered by the external features of the material world and are engaged in the animal propensities of the eat-drink-and-be-merry type of life are simply wasting their lives by the unseen passing away of valuable years. We should know in perfect consciousness that human life is bestowed upon the conditioned soul to achieve spiritual success, and the easiest possible procedure to attain this end is to chant the holy name of the Lord.
(Srimad Bhagavatam-----2:1:12-----purport).

For the perfect yogī who has attained success in the method of leaving his body in perfect consciousness, transferring from one planet to another is as easy as an ordinary man's walking to the grocery store. As already discussed, the material body is just a covering of the spiritual soul. Mind and intelligence are the undercoverings, and the gross body of earth, water, air and so on is the overcoating of the soul. As such, any advanced soul who has realized himself by the yogic process, who knows the relationship between matter and spirit, can leave the gross dress of the soul in perfect order and as he desires. By the grace of God, we have complete freedom. Because the Lord is kind to us, we can live anywhere—either in the spiritual sky or in the material sky, upon whichever planet we desire. However, misuse of this freedom causes one to fall down into the material world and suffer the threefold miseries of conditioned life.
(Sri Caitanya Caritamrta-----1:5:22-----purport).

The embodied soul may be restricted from sense enjoyment, though the taste for sense objects remains. But, ceasing such engagements by experiencing a higher taste, he is fixed in consciousness.
(Bhagavad-Gita-----2:59-----translation).

One who restrains his senses, keeping them under full control, and fixes his consciousness upon Me, is known as a man of steady intelligence.
(Bhagavad-Gita-----2:61-----translation).

A sane man should consult his mind, its thinking, feeling and willing processes, and decide how these processes should be utilized. If one always thinks of Kṛṣṇa, feels how to serve Him and wills to execute the order of Kṛṣṇa, it should be known that he has taken good instruction from his intelligence, which is called the mother. Although the King was refreshed, he nonetheless inquired about his wife. Thus he was consulting, thinking and willing how he could return to his steady good consciousness. The mind may suggest that by viṣaya-bhoga, or sense enjoyment, one can become happy, but when one becomes advanced in Kṛṣṇa consciousness, he does not derive happiness from material activities. This is explained in Bhagavad-gītā (2.59):
viṣayā vinivartante
nirāhārasya dehinaḥ
rasa-varjaṁ raso 'py asya
paraṁ dṛṣṭvā nivartate
"The embodied soul may be restricted from sense enjoyment, though the taste for sense objects remains. But, ceasing such engagements by experiencing a higher taste, he is fixed in consciousness." One cannot be unattached to the sense objects unless he finds better engagement in devotional service. paraṁ dṛṣṭvā nivartate. One can cease from material activities only when one actually engages in devotional service.
(Srimad Bhagavatam-----4:26:14-----purport).

According to this description of the transcendental body of Lord Viṣṇu, the Lord can easily be distinguished from all other living beings. Consequently Mahārāja Nābhi and his priests and associates all offered the Lord obeisances and began to worship Him with various things. As stated in Bhagavad-gītā (6.22), yaṁ labdhvā cāparaṁ lābhaṁ manyate nādhikaṁ tataḥ. That is, "Upon gaining this, one thinks that there is no greater gain." When one realizes God and sees the Lord face to face, one certainly thinks that he has gained the best of all things. Raso 'py asya paraṁ dṛṣṭvā nivartate: (B.G.9:59) when one experiences a higher taste, his consciousness is fixed. After seeing the Supreme Personality of Godhead, one ceases to be attracted by anything material. One then remains steady in his worship of the Supreme Personality of Godhead.
(Srimad Bhagavatam-----5:3:3-----purport).

Purified and fixed in consciousness, the brahmacārī should worship the fire-god, sun, ācārya, cows, brāhmaṇas, guru, elderly respectable persons and demigods. He should perform such worship at sunrise and sunset, without speaking but by silently chanting or murmuring the appropriate mantras.
(Srimad Bhagavatam-----11:17:26-----translation).

When consciousness is fixed on the material body, home and other, similar objects of sense gratification, one spends one's life chasing after material objects with the help of the senses. Consciousness, thus powerfully affected by the mode of passion, becomes dedicated to impermanent things, and in this way irreligion, ignorance, attachment and wretchedness arise.
(Srimad Bhagavatam-----11:19:26-----translation).

The wise man, whose consciousness is fixed in the self, does not even notice his own bodily activities. While standing, sitting, walking, lying down, urinating, eating or performing other bodily functions, he understands that the body is acting according to its own nature.
(Srimad Bhagavatam-----11:28:31-----translation).

How the living entity becomes liberated from the modes of material nature after surrendering unto the Supreme Personality of Godhead is illustrated by the example of a sleeping man within a room. When a man is sleeping, everyone sees that he is present within the room, but actually the man himself is not within that body, for while sleeping a man forgets his bodily existence, although others may see that his body is present. Similarly, a liberated person engaged in devotional service to the Lord may be seen by others to be engaged in the household duties of the material world, but since his consciousness is fixed in Kṛṣṇa, he does not live within this world. His engagements are different, exactly as the sleeping man's engagements are different from his bodily engagements. It is confirmed in the Bhagavad-gītā that a devotee engaged full time in the transcendental loving service of the Lord has already surpassed the influence of the three modes of material nature. He is already situated on the Brahman platform and is in the transcendental realm, although he appears to be living within the body or within the material world.
(Krsna Book).

Spontaneous loving service to the Lord is called devotional service with an intimate attachment between the servitor and the served. This intimacy is called mamatā. Between the servitor and the served there is a feeling of oneness. This mamatā begins with dāsya-prema, service rendered to the master by the servant. Unless there is such a relationship, the loving affairs between the Lord and His devotee are not actually fixed. When the devotee feels "The Lord is my master" and renders service unto Him, Kṛṣṇa consciousness is awakened. This fixed consciousness is on a higher platform than simple cognizance of love of Godhead.
(Sri Caitanya Caritamrta-----2:8:71-----purport).

As stated before, a pure devotee of the Lord has nothing to do with mundane religiosity, economic development, sense gratification, or salvation, nor is he concerned whether his standard of material existence is the highest or the lowest. To him, heaven and hell are of equal value. He is not afraid of going to hell for the service of the Lord, nor is he glad to live in heaven without the service of the Lord. In any circumstance his consciousness is fixed on the Lord's lotus feet, whose beauty defies the most beautiful lotus flower of the mundane world.
(Mukunda Mala Stotra).