Śrī Narottama dāsa Ṭhākura has sung that persons who do not take to the devotional service of the Lord but are attracted to the process of philosophical speculation and fruitive activities drink the poisonous results of such actions. Such persons eat all kinds of obnoxious things, such as meat, and take pleasure in alcohol and other intoxicants, and after death they are forced to take birth in lower species of life. Materialistic persons generally worship the transient material body and forget the welfare of the spirit soul within the body. Some take shelter of materialistic science to improve bodily comforts, and some take to the worship of demigods to be promoted to the heavenly planets. Their goal in life is to make the material body comfortable, but they forget the interest of the spirit soul. Such persons are described in the Vedic literature as suicidal, because attachment for the material body and its comforts forces the living entity to wander through the process of birth and death perpetually and suffer the material pangs as a matter of course. The human form of life is a chance for one to understand his position. Therefore the most intelligent person takes to devotional service just to engage his mind, senses and body in the service of the Lord without deviation.
The personified Vedas continued: "Dear Lord, there are many mystic yogīs who are very learned and deliberate in achieving the highest perfection of life. They engage themselves in the yogic process of controlling the life air within the body. Concentrating the mind upon the form of Viṣṇu and controlling the senses very rigidly, they practice the yoga system, but even after much laborious austerity, penance and regulation, they achieve the same destination as persons inimical toward You. In other words, both the yogīs and the great, wise philosophical speculators ultimately attain the impersonal Brahman effulgence, which is automatically attained by the demons who are regular enemies of the Lord. Demons like Kaṁsa, Śiśupāla and Dantavakra attain the Brahman effulgence because they constantly meditate upon the Supreme Personality of Godhead out of enmity. The real point is to concentrate the mind on the Supreme Personality of Godhead. Women such as the gopīs were attached to Kṛṣṇa, being captivated by His beauty, and their mental concentration on Kṛṣṇa was provoked by lust. They wanted to be embraced by the arms of Kṛṣṇa, which resemble the beautiful round shape of a snake. Similarly, we, the Vedic hymns, simply concentrate our minds on the lotus feet of Your Lordship. Women like the gopīs concentrate upon You under the dictation of lust, and we concentrate upon Your lotus feet to go back home, back to Godhead. Your enemies also concentrate upon You, thinking always of how to kill You, and yogīs undertake great penances and austerities just to attain Your impersonal effulgence. All these different persons, although concentrating their minds in different ways, achieve spiritual perfection according to their different perspectives because You, O Lord, are equal to all Your devotees."
Śrīdhara Svāmī has composed a nice verse in this regard: "My dear Lord, to be engaged always in thinking of Your lotus feet is very difficult. It is possible for great devotees who have already achieved love for You and are engaged in transcendental loving service. My dear Lord, I wish that my mind may also be fixed somehow or other on Your lotus feet, at least for some time."
The attainment of spiritual perfection by different spiritualists is explained in the Bhagavad-gītā, wherein the Lord says that He grants the perfection the devotee desires in proportion to the devotee's surrender unto Him. The impersonalists, yogīs and enemies of the Lord enter into the Lord's transcendental effulgence, but the personalists who follow in the footsteps of the inhabitants of Vṛndāvana or strictly follow the path of devotional service are elevated to the personal abode of Kṛṣṇa, Goloka Vṛndāvana, or to the Vaikuṇṭha planets. Both the impersonalists and the personalists enter the spiritual realm, the spiritual sky, but the impersonalists are given their place in the impersonal Brahman effulgence, whereas the personalists are given a position in the Vaikuṇṭha planets or in the Vṛndāvana planet, according to their desire to serve the Lord in different mellows.
The personified Vedas stated that persons born after the creation of this material world cannot understand the existence of the Supreme Personality of Godhead by manipulating their material knowledge. Just as a person born in a particular family cannot understand the position of his great-grandfather, who lived before the birth of the recent generation, we are unable to understand the Supreme Personality of Godhead, Nārāyaṇa, or Kṛṣṇa, who exists eternally in the spiritual world. In the Eighth Chapter of the Bhagavad-gītā it is clearly said that the Supreme Person, who lives eternally in the spiritual kingdom of God (sanātana-dhāma), can be approached only by devotional service.
As for the material creation, Brahmā is the first created person. Before Brahmā there was no living creature within this material world; it was void and dark until Brahmā was born on the lotus flower that sprouted from the abdomen of Garbhodakaśāyī Viṣṇu. Garbhodakaśāyī Viṣṇu is an expansion of Kāraṇodakaśāyī Viṣṇu, Kāraṇodakaśāyī Viṣṇu is an expansion of Saṅkarṣaṇa, and Saṅkarṣaṇa is an expansion of Balarāma, who is an immediate expansion of Lord Kṛṣṇa. After the creation of Brahmā, the two kinds of demigods were born: demigods like the four brothers Sanaka, Sanātana, Sanandana and Sanat-kumāra, who are representatives of renunciation of the world, and demigods like Marīci and their descendants, who are meant to enjoy this material world. From these two kinds of demigods were gradually manifested all other living entities, including the human beings. Thus all living creatures within this material world, including Brahmā, all the demigods and all the Rākṣasas, are to be considered modern. This means that they were all born recently. Therefore, just as a person born recently in a family cannot understand the situation of his distant forefather, no one within this material world can understand the position of the Supreme Lord in the spiritual world, because the material world has only recently been created. Although they have a long duration of existence, all the manifestations of the material world—namely the time element, the living entities, the Vedas and the gross and subtle material elements—are created at some point. Thus any process manufactured within this created situation as a means for understanding the original source of creation is to be considered modern.
Therefore by the process of self-realization or God realization through fruitive activities, philosophical speculation or mystic yoga, one cannot actually approach the supreme source of everything. When the creation is completely terminated—when there is no existence of the Vedas, no existence of material time, and no existence of the gross and subtle material elements, and when all the living entities are in the nonmanifested stage, resting within Nārāyaṇa—then all these manufactured processes become null and void and cannot act. Devotional service, however, is eternally going on in the eternal spiritual world. Therefore the only factual process of self-realization or God realization is devotional service, and one who takes to this process takes to the real process of God realization.