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.