SB 4.30.18
atha mayy anapayinya
bhaktya pakva-gunasayah
upayasyatha mad-dhama
nirvidya nirayad atah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thereafter you will develop unadulterated devotional service unto Me and be freed from all material contamination. At that time, being completely unattached to material enjoyment in the so-called heavenly planets as well as in hellish planets, you will return home, back to Godhead.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
By the grace of the Lord, the Pracetas were given special facilities. Although they could live millions of years to enjoy material facilities, they still would not be deviated from the transcendental loving service of the Lord. Being thus fully engaged, the Pracetas would be completely freed from all material attachment. Material attachment is very strong. During one lifetime, a materialist engages in acquiring land, money, friends, society, friendship, love and so on. He also wants to enjoy the heavenly planets after the annihilation of the body. If one is engaged in devotional service, however, he becomes unattached to all kinds of material enjoyment and suffering. In the material world, those who are elevated to the higher planetary systems are supposed to enjoy all material facilities, whereas those degraded to lower planetary systems are supposed to live in a hellish condition. A devotee, however, is transcendental to both heavenly and hellish conditions. According to Bhagavad-gita (14.26), a devotee’s position is described in this way:
mam ca yo ’vyabhicarena
bhakti-yogena sevate
sa gunan samatityaitan
brahma-bhuyaya kalpate
“One who engages in full devotional service, who does not fall down in any circumstance, at once transcends the modes of material nature and thus comes to the level of Brahman.”
A devotee is always situated on the Brahman platform. He has nothing to do with material happiness or distress. When one is strongly fixed in devotional service and free from all material attachment, uncontaminated by the material modes of nature, he becomes fit to return home, back to Godhead. Although by special blessing the Pracetas would enjoy material facilities for millions of years, they would not be attached to them. Thus at the end of their material enjoyment they would be promoted to the spiritual world and return to Godhead.
The word pakva-gunasayah has special significance, for it means that by devotional service one is able to give up the influence of the three modes of material nature. As long as one is influenced by the modes of material nature, he cannot return to Godhead. It is clearly explained that all planets in the material world — beginning from Brahmaloka down to the hellish planets — are unfit places for a devotee. Padam padam yad vipadam na tesam. A place where there is danger at every step is certainly not a comfortable place. The Lord therefore says in Bhagavad-gita (8.16):
abrahma-bhuvanal lokah
punar avartino ’rjuna
mam upetya tu kaunteya
punar janma na vidyate
“From the highest planet in the material world down to the lowest, all are places of misery wherein repeated birth and death take place. But one who attains to My abode, O son of Kunti, never takes birth again.”
Thus there is no profit, even if one is promoted to the highest planet in the material universe, Brahmaloka. However, if one is somehow or other promoted to the abode of the Lord, he never returns to the material world.