Krishna, God, the Supreme Person says:
Because I desire that human beings attain perfection, I have introduced three ways of elevation, the way of knowledge, the way of action and the way of devotion. Besides these three, there is absolutely no other way of elevation. Among these three paths, the path of philosophical speculation is recommended to those who are disgusted with material life and thus detach themselves from ordinary fruitful activities. Those who are not disgusted with the material life, still having many desires to fulfill, should seek perfection through the path of devotional service. If somehow by chance one develops faith by hearing and chanting My glories, such a person, neither disgusted nor very attached to the material life, should attain perfection by way of l love and devotion to Me.
As long as one is not satisfied by a fruitful activity and one has not awakened his taste for pure devotional service, one must act according to the regulating principles of Vedic injunctions (from the Vedas, the original holy scriptures). A person who is situated in his prescribed duty, worshiping correctly through Vedic sacrifices but not desiring the fruitful result of worship, will not go to the celestial planets. Likewise, by not performing prohibited activities, he will not go to hell.
He who is situated in his prescribed duty, free from all sinful activity and free from all material contamination, obtains in this very life a transcendental knowledge or, by fortune, a devotional service towards Me. The residents of heaven and hell desire human birth on planet Earth because human life facilitates the attainment of transcendent knowledge and love of God, while neither the heavenly bodies nor the underworld effectively provide such opportunities.
A wise human being should never desire promotion to the heavenly planets [Edenic, paradisiacal] or a residence in hell. Indeed, a human being should not desire a permanent residence on earth either, because by such absorption in the material body, one becomes stupidly neglectful of his own personal interest.
The sage knowing well that the material body is subject at death he can still come to the perfection of his life, and should not foolishly neglect to take advantage of this opportunity before death arrives. Without attachment, a bird abandons the tree in which its nest was built when that tree is cut down by cruel men who are like death personified, and so the bird attains happiness in another place. Knowing that its lifespan is also reduced by the passage of days and nights, it can be shaken by fear. In this way, by letting go of all attachment and material desire, one understands the Supreme Lord and one achieves perfect peace.
The human body, which can bestow all the benefits of life is automatically obtained by the laws of nature material, although this is a very rare achievement [for it is very rare for a soul to obtain a human body]. This human body can be compared to a perfectly constructed boat having the spiritual master as captain and the Supreme Person's instructions as the auspicious winds driving it on its way. Considering all