Srimad Bhagavatam Canto 04, Chapter 24, Text 29

SB 4.24.29

sva-dharma-nisthah sata-janmabhih puman
 viriñcatam eti tatah param hi mam
avyakrtam bhagavato ’tha vaisnavam
 padam yathaham vibudhah kalatyaye
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
A person who executes his occupational duty properly for one hundred births becomes qualified to occupy the post of Brahma, and if he becomes more qualified, he can approach Lord Siva. A person who is directly surrendered to Lord Krsna, or Visnu, in unalloyed devotional service is immediately promoted to the spiritual planets. Lord Siva and other demigods attain these planets after the destruction of this material world.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
This verse gives an idea of the highest perfection of the evolutionary process. As described by the Vaisnava poet Jayadeva Gosvami, pralaya-payodhi-jale dhrtavan asi vedam. Let us begin tracing the evolutionary process from the point of devastation (pralaya), when the whole universe is filled with water. At that time there are many fishes and other aquatics, and from these aquatics evolve creepers, trees, etc. From these, insects and reptiles evolve, and from them, birds, beasts and then human beings and finally civilized human beings. Now, the civilized human being is at a junction where he can make further evolutionary progress in spiritual life. Here it is stated (sva-dharma-nisthah) that when a living entity comes to a civilized form of life, there must be sva-dharma, social divisions according to one’s work and qualifications. This is indicated in Bhagavad-gita (4.13):
catur-varnyam maya srstam
“According to the three modes of material nature and the work ascribed to them, the four divisions of human society were created by Me.”
In civilized human society there must be the divisions of brahmana, ksatriya, vaisya and sudra, and everyone must properly execute his occupational duty in accordance with his division. Here it is described (sva-dharma-nisthah) that it does not matter whether one is a brahmana, ksatriya, vaisya or sudra. If one sticks to his position and properly executes his particular duty, he is considered a civilized human being. Otherwise he is no better than an animal. It is also mentioned herein that whoever executes his occupational duty (sva-dharma) for one hundred births (for instance, if a brahmana continues to act as a brahmana) becomes eligible for promotion to Brahmaloka, the planet where Lord Brahma lives. There is also a planet called Sivaloka, or Sadasivaloka, which is situated in a marginal position between the spiritual and material worlds. If, after being situated in Brahmaloka, one becomes more qualified, he is promoted to Sadasivaloka. Similarly, when one becomes even more qualified, he can attain the Vaikunthalokas. The Vaikunthalokas are targets for everyone, even the demigods, and they can be attained by a devotee who has no desire for material benefit. As indicated in Bhagavad-gita (8.16), one does not escape material miseries even if he is elevated to Brahmaloka (abrahma-bhuvanal lokah punar avartino ’rjuna). Similarly, one is not very safe even if he is promoted to Sivaloka, because the planet of Sivaloka is marginal. However, if one attains Vaikunthaloka, he attains the highest perfection of life and the end of the evolutionary process (mam upetya tu kaunteya punar janma na vidyate). In other words, it is confirmed herein that a person in human society who has developed consciousness must take to Krsna consciousness in order to be promoted to Vaikunthaloka or Krsnaloka immediately after leaving the body. Tyaktva deham punar janma naiti mam eti so ’rjuna (Bg. 4.9). A devotee who is fully in Krsna consciousness, who is not attracted by any other loka, or planet, including Brahmaloka and Sivaloka, is immediately transferred to Krsnaloka (mam eti). That is the highest perfection of life and the perfection of the evolutionary process.
Srimad Bhagavatam Canto 04, Chapter 24, Text 28
Srimad Bhagavatam Canto 04, Chapter 24, Text 30