1568
Śrīmad-Bhāgavatam
[Canto 4, Ch. 31]
born a  kṣatriya  or  vaiśya  or even lower, and, in the eighteenth year, attaining elevation to the brahminical platform by the process of initiation. Therefore Nārada Muni says:
yasya yal lakṣaṇam proktam pumso varṇābhivyañjakam yad anyatrāpi dṛśyeta tat tenaiva vinirdiśet (Bhāg. 7.11.35)
It is not a fact that because one is born in a  brāhmaṇa  family he is automatically a  brāhmaṇa . He has a better chance to become a  brāhmaṇa , but unless he meets all the brahminical qualifications, he cannot be accepted as such. On the other hand, if the brahminical qualifications are found in the person of a  śūdra , he should immediately be accepted as a  brāhmaṇa . To substantiate this there are many quotations from  Bhāgavatam ,  Mahābhārata ,  Bharadvāja-saṁhitā  and the  Pañcarātra , as well as many other scriptures.
As far as the duration of life of the demigods, concerning Lord Brahmā it is said:
sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ rātrim yuga-sahasrāntām te 'ho-rātra-vido janāḥ (Bg. 8.17)
The duration of one day of Brahmā is one thousand times greater than the four  yugas  aggregating to 4,300,000 years. Similarly, Brahmā's one night. Brahmā lives for one hundred years of such days and nights. The word  vibudhāyuṣā  indicates that even if one gets a long life span, his life span is useless if he is not a devotee. A living entity is the eternal servitor of the Supreme Lord, and unless he comes to the platform of devotional service, his life span, good birth, glorious activities and everything else are null and void.
TEXT 11
भुतेन तपसा वा किं वचोभिश्चित्तवृत्तिभिः । बुद्ध्या वा किं निपुण्या बलेनेन्द्रियराधसा ॥११॥
śrutena tapasā vā kim vacobhiś citta-vṛttibhiḥ buddhyā vā kim nipuṇayā balenendriya-rādhasā