The ultimate goal in practicing yoga is now clearly explained. Yoga practice is not meant for attaining any kind of material facility; it is to enable the cessation of all material existence. One who seeks an improvement in health or aspires after material perfection is no yogī according to Bhagavad-gītā. Nor does cessation of material existence entail one's entering into "the void," which is only a myth. There is no void anywhere within the creation of the Lord. Rather, the cessation of material existence enables one to enter into the spiritual sky, the abode of the Lord. The abode of the Lord is also clearly described in the Bhagavad-gītā as that place where there is no need of sun, moon or electricity. All the planets in the spiritual kingdom are self-illuminated like the sun in the material sky. The kingdom of God is everywhere, but the spiritual sky and the planets thereof are called paraṁ dhāma, or superior abodes.
(Bhagavad-Gita----6:15-----purport).

It is only a matter of understanding and accepting the fact. Khaṭvāṅga Mahārāja attained this state of life just a few minutes before his death, by surrendering unto Kṛṣṇa. Nirvāṇa means ending the process of materialistic life. According to Buddhist philosophy, there is only void after the completion of this material life, but Bhagavad-gītā teaches differently. Actual life begins after the completion of this material life. For the gross materialist it is sufficient to know that one has to end this materialistic way of life, but for persons who are spiritually advanced, there is another life after this materialistic life. Before ending this life, if one fortunately becomes Kṛṣṇa conscious, he at once attains the stage of brahma-nirvāṇa. There is no difference between the kingdom of God and the devotional service of the Lord.
(Bhagavad-Gita----2:72-----purport).

This last class of men take to the shelter of some kind of intoxication, and their affective hallucinations are sometimes accepted as spiritual vision. One has to get rid of all three stages of material consciousness: attachment to material life, fear of a spiritual personal identity, and the conception of void that arises from frustration in life. To get free from these three stages of the material concept of life, one has to take complete shelter of the Lord, guided by the bona fide spiritual master, and follow the disciplines and regulative principles of devotional life. The last stage of the devotional life is called bhāva, or transcendental love of Godhead.
(Bhagavad-Gita----4:10-----purport).

Furthermore there are many persons who cannot understand spiritual existence at all. Being embarrassed by so many theories and by contradictions of various types of philosophical speculation, they become disgusted or angry and foolishly conclude that there is no supreme cause and that everything is ultimately void. Such people are in a diseased condition of life.
(Bhagavad-Gita----4:10-----purport).

The process of thinking of the Supreme is mentioned in this verse. The foremost point is that He is not impersonal or void. One cannot meditate on something impersonal or void. That is very difficult. The process of thinking of Kṛṣṇa, however, is very easy and is factually stated herein. First of all, the Lord is puruṣa, a person—we think of the person Rāma and the person Kṛṣṇa. And whether one thinks of Rāma or of Kṛṣṇa, what He is like is described in this verse of Bhagavad-gītā. The Lord is kavi; that is, He knows past, present and future and therefore knows everything. He is the oldest personality because He is the origin of everything; everything is born out of Him. He is also the supreme controller of the universe, and He is the maintainer and instructor of humanity.
(Bhagavad-Gita----8:9-----purport).

Every incarnation of the Lord has His own abode in the spiritual sky. Therefore Lord Kapila also has His separate Vaikuṇṭha planet. The spiritual sky is not void. There are innumerable Vaikuṇṭha planets, and in each of them the Lord, by His innumerable expansions, predominates, and the pure devotees who are there also live in the same style as the Lord and His eternal associates.
When the Lord descends personally or by His personal plenary expansions, such incarnations are called aṁśa, kalā, guṇa, yuga and manvantara incarnations, and when the Lord's associates descend by the order of the Lord, such incarnations are called śaktyāveśa incarnations. But in all cases all the incarnations are supported by the invulnerable statements of the authorized scriptures, and not by any imagination of some self-interested propagandist.
(Srimad Bhagavatam-----2:7:3-----purport).

The most unfortunate persons are the impersonalists, who cannot understand the transcendental variegatedness of the spiritual world. They are afraid to talk about the beauty of the Vaikuṇṭha planets because they think that variegatedness must be material. Such impersonalists think that the spiritual world is completely void, or, in other words, that there is no variegatedness. This mentality is described here as ku-kathā mati-ghnīḥ, "intelligence bewildered by unworthy words." The philosophies of voidness and of the impersonal situation of the spiritual world are condemned here because they bewilder one's intelligence. How can the impersonalist and the void philosopher think of this material world, which is full of variegatedness, and then say that there is no variegatedness in the spiritual world? It is said that this material world is the perverted reflection of the spiritual world, so unless there is variegatedness in the spiritual world, how can there be temporary variegatedness in the material world?
(Srimad Bhagavatam-----3:15:23-----purport).

Actually all living entities are provided for and maintained by the Lord because He is the supreme living entity. But foolish creatures, although actually under the control of the supreme living entity, defy His existence, and that state is called māyā. Sometimes they deny that there is such a being as God. They say, "Everything is void." And sometimes they deny Him in a different way: "There may be a God, but He has no form." Both these conceptions arise from the rebellious condition of the living entity. As long as this rebellious condition prevails, the material world will continue in disharmony.
(Srimad Bhagavatam-----3:15:33-----purport).

As explained in the Nārada Pañcarātra, one's mind and senses should be purified (tat-paratvena nirmalam (CC.2:19:170). One's senses must be engaged in devotional service to the Lord. That is the process. The mind must have some engagement. One cannot make the mind vacant. Of course there are some foolish attempts to try to make the mind vacant or void, but that is not possible. The only process that will purify the mind is to engage it in Kṛṣṇa. The mind must be engaged. If we engage our mind in Kṛṣṇa, naturally the consciousness becomes fully purified, and there is no chance of the entrance of material desire and greed.
(Srimad Bhagavatam-----3:25:16-----purport).

When one becomes envious of Kṛṣṇa, or the Supreme Personality of Godhead, one thinks, "Why should Kṛṣṇa be the all and all? I'm as good as Kṛṣṇa." These two items, desire to be the Lord and envy of the Lord, are the beginning cause of material bondage. As long as a philosopher, salvationist or voidist has some desire to be supreme, to be everything, or to deny the existence of God, the cause remains, and there is no question of his liberation.
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. There is a gulf of difference between theoretical freedom and actual freedom from material bondage.
(Srimad Bhagavatam-----3:27:20-----purport).

The essential point is that the mind, which is contaminated by material attraction, has to be bridled and concentrated on the Supreme Personality of Godhead. It cannot be fixed on something void or impersonal. For this reason, so-called yoga practices of voidism and impersonalism are not recommended in any standard yoga-śāstra. The real yogī is the devotee because his mind is always concentrated on the pastimes of Lord Kṛṣṇa. Therefore Kṛṣṇa consciousness is the topmost yoga system.
(Srimad Bhagavatam-----3:28:7-----purport).

Because of material contamination, all the propensities we feel in the material world are ever unsatisfied. But when our desires to see, hear, touch, etc., are dovetailed for the satisfaction of the Supreme Personality of Godhead, they are on the level of the topmost perfection.
Although the Supreme Personality of Godhead in His eternal form is so beautiful and pleasing to the heart of the devotee, He does not attract the impersonalists, who want to meditate on His impersonal aspect. Such impersonal meditation is simply fruitless labor. The actual yogīs, with half-closed eyes, fix on the form of the Supreme Personality of Godhead, not upon anything void or impersonal.
(Srimad Bhagavatam-----3:28:16-----purport).

Meditating on the lotus feet of the Lord acts like a thunderbolt on the mountain of dirt in the mind of the yogī. If a yogī wants to shatter the mountain of dirt in his mind, he should concentrate on the lotus feet of the Lord and not imagine something void or impersonal. Because the dirt has accumulated like a solid mountain, one must meditate on the lotus feet of the Lord for quite a long time. For one who is accustomed to thinking of the lotus feet of the Lord constantly, however, it is a different matter. The devotees are so fixed on the lotus feet of the Lord that they do not think of anything else. Those who practice the yoga system must meditate on the lotus feet of the Lord for a long time after following the regulative principles and thereby controlling the senses.
(Srimad Bhagavatam-----3:28:22-----purport).