CC Ādi 5.14

prakṛtira pāra ‘paravyoma’-nāme dhāma
kṛṣṇa-vigraha yaiche vibhūty-ādi-guṇavān
Word for word: 
prakṛtira — the material nature; pāra — beyond; para-vyoma — the spiritual sky; nāme — in name; dhāma — the place; kṛṣṇa-vigraha — the form of Lord Kṛṣṇa; yaiche — just as; vibhūti-ādi — like the six opulences; guṇa-vān — full with transcendental attributes.
Translation: 
Beyond the material nature lies the realm known as paravyoma, the spiritual sky. Like Lord Kṛṣṇa Himself, it possesses all transcendental attributes, such as the six opulences.
Purport: 

According to Sāṅkhya philosophy, the material cosmos is composed of twenty-four elements: the five gross material elements, the three subtle material elements, the five knowledge-acquiring senses, the five active senses, the five objects of sense pleasure, and the mahat-tattva (the total material energy). Empiric philosophers, unable to go beyond these elements, speculate that anything beyond them must be avyakta, or inexplicable. But the world beyond the twenty-four elements is not inexplicable, for it is explained in the Bhagavad-gītā as the eternal (sanātana) nature. Beyond the manifested and unmanifested existence of material nature (vyaktāvyakta) is the sanātana nature, which is called the paravyoma, or the spiritual sky. Since that nature is spiritual in quality, there are no qualitative differences there: everything there is spiritual, everything is good, and everything possesses the spiritual form of Śrī Kṛṣṇa Himself. That spiritual sky is the manifested internal potency of Śrī Kṛṣṇa; it is distinct from the material sky, manifested by His external potency.

The all-pervading Brahman, composed of the impersonal glowing rays of Śrī Kṛṣṇa, exists in the spiritual world with the Vaikuṇṭha planets. We can get some idea of that spiritual sky by a comparison to the material sky, for the rays of the sun in the material sky can be compared to the brahmajyoti, the glowing rays of the Personality of Godhead. In the brahmajyoti there are unlimited Vaikuṇṭha planets, which are spiritual and therefore self-luminous, with a glow many times greater than that of the sun. The Personality of Godhead Śrī Kṛṣṇa, His innumerable plenary portions and the portions of His plenary portions dominate each Vaikuṇṭha planet. In the highest region of the spiritual sky is the planet called Kṛṣṇaloka, which has three divisions, namely Dvārakā, Mathurā and Goloka, or Gokula.

To a gross materialist this kingdom of God, Vaikuṇṭha, is certainly a mystery. But to an ignorant man everything is a mystery for want of sufficient knowledge. The kingdom of God is not a myth. Even the material planets, which float over our heads in the millions and billions, are still a mystery to the ignorant. Material scientists are now attempting to penetrate this mystery, and a day may come when the people of this earth will be able to travel in outer space and see the variegatedness of these millions of planets with their own eyes. In every planet there is as much material variegatedness as we find in our own planet.

This planet earth is but an insignificant spot in the cosmic structure. Yet foolish men, puffed up by a false sense of scientific advancement, have concentrated their energy in the pursuit of so-called economic development on this planet, not knowing of the variegated economic facilities available on other planets. According to modern astronomy, the gravity of the moon is different from that of earth. Therefore one who goes to the moon will be able to pick up large weights and jump vast distances. In the Rāmāyaṇa, Hanumān is described as being able to lift huge weights as heavy as hills and jump over the ocean. Modern astronomy has confirmed that this is indeed possible.

The disease of the modern civilized man is his disbelief of everything in the revealed scriptures. Faithless nonbelievers cannot make progress in spiritual realization, for they cannot understand the spiritual potency. The small fruit of a banyan contains hundreds of seeds, and in each seed is the potency to produce another banyan tree with the potency to produce millions more of such fruits. This law of nature is visible before us, although how it works is beyond our understanding. This is but an insignificant example of the potency of Godhead; there are many similar phenomena that no scientist can explain.

Everything, in fact, is inconceivable, for the truth is revealed only to the proper persons. Although there are varieties of personalities, from Brahmā down to the insignificant ant, all of whom are living beings, their development of knowledge is different. Therefore we have to gather knowledge from the right source. Indeed, in reality we can get knowledge only from the Vedic sources. The four Vedas, with their supplementary Purāṇas, the Mahābhārata, the Rāmāyaṇa and their corollaries, which are known as smṛtis, are all authorized sources of knowledge. If we are at all to gather knowledge, we must gather it from these sources without hesitation.

Revealed knowledge may in the beginning be unbelievable because of our paradoxical desire to verify everything with our tiny brains, but the speculative means of attaining knowledge is always imperfect. The perfect knowledge propounded in the revealed scriptures is confirmed by the great ācāryas, who have left ample commentations upon them; none of these ācāryas has disbelieved in the śāstras. One who disbelieves in the śāstras is an atheist, and we should not consult an atheist, however great he may be. A staunch believer in the śāstras, with all their diversities, is the right person from whom to gather real knowledge. Such knowledge may seem inconceivable in the beginning, but when put forward by the proper authority its meaning is revealed, and then one no longer has any doubts about it.