The Lord, therefore, is always giving instruction from within and from without. From without He gives instructions as stated in Bhagavad-gītā, and from within He tries to convince the living entity that his activities in the material field are not conducive to real happiness. "Just give it up and turn your faith toward Me. Then you will be happy," He says. Thus the intelligent person who places his faith in the Paramātmā or the Supreme Personality of Godhead begins to advance toward a blissful eternal life of knowledge.
(Bhagavad-Gita---13:23----purport).

By his personal endeavor in association with authorities, saintly persons and a spiritual master, he has to understand his position and then revert to spiritual consciousness or Kṛṣṇa consciousness by understanding Bhagavad-gītā as it is explained by the Personality of Godhead. Then it is certain that he will never come again into this material existence; he will be transferred into the spiritual world for a blissful eternal life of knowledge.
(Bhagavad-Gita---13:24----purport).

The living entities serving material energy are struggling hard for existence and happiness, which is presented to them as illusion. But those in the spiritual energy are placed under the direct service of the Lord in eternal life, complete knowledge and perpetual bliss.
(Srimad Bhagavatam---1:5:31----purport).

The systematic hearing of the transcendental activities, qualities and names of Lord Śrī Kṛṣṇa pushes one towards eternal life. Systematic hearing means knowing Him gradually in truth and fact, and this knowing Him in truth and fact means attaining eternal life, as stated in the Bhagavad-gītā. Such transcendental, glorified activities of Lord Śrī Kṛṣṇa are the prescribed remedy for counteracting the process of birth, death, old age and disease, which are considered to be material awards for the conditioned living being.
(Srimad Bhagavatam---1:18:10----purport).

Every one of us is searching after real happiness in life, namely eternal life, eternal or unlimited knowledge and unending blissful life. But foolish people who have no knowledge of the substance search after the reality of life in the illusion. This material body does not endure eternally, and everything in relation with this temporary body, such as the wife, children, society and country, also changes along with the change of body.
(Srimad Bhagavatam---2:2:6----purport).

Life is solely meant for tapasya, for purifying existence so that one may enter into eternal life just after the end of the human form of life.
(Srimad Bhagavatam---2:3:18----purport).

The lokas, or different planets, are attractive because they have different varieties of life and bliss partially representing the sac-cid-ānanda-vigraha (Bs. 5.1). Everyone wants the eternal life of bliss and knowledge. In the material world such an eternal life of bliss and knowledge is progressively realized in the upper planets, but after reaching there one is inclined to achieve further progress along the path back to Godhead.
(Srimad Bhagavatam---2:5:15----purport).

The Lord wants every one of His parts and parcels to attain eternal life and bliss by coming home to Godhead, and the whole material creation is meant for that objective. Brahmā underwent severe penances for that purpose, namely to regulate the process of creation so that the Lord might be satisfied. Therefore the Lord was very much pleased with him, and for this Brahmā was impregnated with Vedic knowledge.
(Srimad Bhagavatam---2:9:20----purport).

The only means to attain eternal life is to go back home, back to Godhead, where there is no more rebirth as in the material planets. The conditioned souls, being unaware of this very simple fact because of forgetting their relationship with the Lord of Vaikuṇṭha, try to plan out a permanent life in this material world.
(Srimad Bhagavatam---2:10:4----purport).

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.
(Srimad Bhagavatam---3:15:45----purport).

We should always feel very much obliged to the Personality of Godhead, for He is always anxious to bring us into the happy condition of eternal life. There is no sufficient means to repay the Personality of Godhead for His act of benediction; therefore, we can simply feel gratitude and pray to the Lord with folded hands.
(Srimad Bhagavatam---3:31:18----purport).

Even in this material world the so-called scientists, philosophers and mental speculators strive to merge into the spiritual sky, but they can never go there. But a devotee, by executing devotional service, not only realizes what the spiritual world actually is, but factually goes there to live an eternal life of bliss and knowledge. The Kṛṣṇa consciousness movement is so potent that by adopting these principles of life and developing love of God one can very easily go back home, back to Godhead.
(Srimad Bhagavatam---4:12:25----purport).

Time is eternal, and in the material world one passes through different phases of his eternal life. Time is compared herein to a sharp razor. A razor is meant to shave the hair from one's face, but if not carefully handled, the razor will cause disaster. One is advised not to create a disaster by misusing his lifetime. One should be extremely careful to utilize the span of his life for spiritual realization, or Kṛṣṇa consciousness.
(Srimad Bhagavatam---6:5:19----purport).

Everyone is wandering up and down within this universe, but one who is sufficiently fortunate comes in contact with Kṛṣṇa consciousness, by the mercy of the spiritual master, and takes to the path of devotional service. Then one is assured of eternal life, with no fear of death. When Kṛṣṇa appears, everyone is freed from fear of death, yet Devakī felt, "We are still afraid of Kaṁsa, although You have appeared as our son." She was more or less bewildered as to why this should be so, and she appealed to the Lord to free her and Vasudeva from this fear.
(Srimad Bhagavatam---10:3:27----purport).

The fulfillment of human life is summarized in this verse from Śrīmad-Bhāgavatam (10.82.44). There are two important words in this verse: bhakti (devotional service) and amṛtatva (eternal life). The aim of human life is to attain the natural position of eternal life. This eternal life can be achieved only by devotional service.
(Sri Caitanya Caritamrta----2:8:90----purport).

The Supreme Lord is as much an individual as other living beings, but He is different in that He is the Supreme and all other living beings are subordinate to Him. All other living beings can also enjoy spiritual bliss, eternal life and full knowledge in His association. Lord Caitanya quotes a verse from Bhagavad-gītā in which Kṛṣṇa, telling Arjuna of His different opulences, points out that He Himself enters this universe by one of His plenary portions, Garbhodakaśāyī Viṣṇu, and also enters into each universe as the Kṣīrodakaśāyī Viṣṇu, and then expands Himself as the Supersoul in everyone's heart.
(Teachings of Lord Caitanya).

When devotional service is performed with our present senses, it is called practical devotional service. Actually devotional service is the eternal life of the living entity and is lying dormant in everyone's heart. The practice which invokes that dormant devotional service is called practical devotional service. The purport is that the living entity is constitutionally part and parcel of the Supreme Lord; the Lord can be compared to the sun, and the living entities can be compared to molecules of sunshine. Under the spell of illusory energy, the spiritual spark is almost extinguished, but by practical devotional service one can revive his natural constitutional position.
(Teachings of Lord Caitanya).

The highest planet of the material universe, Brahmaloka, is also subjected to these modes of nature, although the duration of life on that planet, due to the predominance of the mode of sattva, is said to be 4,300,000 x 1,000 x 2 x 30 x 12 x 100 solar years. Despite this long duration, however, Brahmaloka is subject to destruction. Although life on Brahmaloka is fantastically long compared to life on Earth, it is only a flash in comparison to the eternal life of the nonmaterial worlds. Consequently, the speaker of the Bhagavad-gītā, Lord Śrī Kṛṣṇa, asserts the importance of the antimaterial universe, which is His abode.
(Easy Journey to Other Planets).

Exactly as material atoms create the material world, the antimaterial atoms create the antimaterial world with all its paraphernalia. The antimaterial world is inhabited by antimaterial living beings. In the antimaterial world there is no inert matter. Everything there is a living principle, and the Supreme Personality in that region is God Himself. The denizens of the antimaterial world possess eternal life, eternal knowledge and eternal bliss. In other words, they have all the qualifications of God.
(Easy Journey to Other Planets).

For example, when a man falls ill, he goes to a physician who prescribes medicines which eventually cure the suffering patient. Similarly, the materialist is ailing, and he should consult an expert transcendentalist-physician. What is his ailment? He is suffering the tribulations of repeated births, deaths, diseases and old age. Once he agrees to put himself under the "back to Godhead" treatment, he is able to transfer himself to the antimaterial world, where there is eternal life instead of birth and death.
(Easy Journey to Other Planets).

Man's desire to be deathless is realized only in the spiritual world. As stated at the beginning of this essay, a desire for eternal life is a sign of dormant spiritual life. The aim of human civilization should be targeted to that end. It is possible for every human being to transfer himself to that spiritual realm by the process of bhakti-yoga, as described herein. It is a great science, and India has produced many scientific literatures by which the perfection of life may be realized.
(Easy Journey to Other Planets).

A human body exists one hundred years, whereas an insect body may exist for twelve hours. Thus the duration of these different bodies is relative. If one enters the planet called Vaikuṇṭhaloka, the spiritual planet. however, he then achieves eternal life, full of bliss and knowledge. A human being can attain that perfection if he tries. That is stated in Bhagavad-gītā when the Lord says, "Anyone who knows in truth about the Supreme Personality of Godhead can attain to My nature."
(Easy Journey to Other Planets).