1566
Śrīmad-Bhāgavatam
[Canto 4, Ch. 31]
karmabhir vā trayī-proktaiḥ puṁso 'pi vibudhāyuṣā
kim —what is the use;  janmabhiḥ —of births;  tribhiḥ —three;  vā —or;  iha —in this world;  śaukra —by semina;  sāvitra —by initiation;  yājñikaiḥ —by becoming a perfect  brāhmaṇa ;  karmabhiḥ —by activities;  vā —or;  trayī —in the  Vedas ;  proktaiḥ —instructed;  puṁsaḥ —of a human being;  api —even;  vibudha —of the demigods;  āyuṣā —with a duration of life.
TRANSLATION
A civilized human being has three kinds of births. The first birth is by a pure father and mother, and this birth is called birth by semina. The next birth takes place when one is initiated by the spiritual master, and this birth is called  sāvitra . The third birth, called  yājñika , takes place when one is given the opportunity to worship Lord Viṣṇu. Despite the opportunities for attaining such births, even if one gets the lifespan of a demigod, if one does not actually engage in the service of the Lord, everything is useless. Similarly, one's activities may be mundane or spiritual, but they are useless if they are not meant for satisfying the Lord.
PURPORT
The word  śaukra-janma  means taking birth by seminal discharge. Animals can take their birth in this way too. However, a human being can be reformed from the  śaukra-janma , as recommended in the Vedic civilization. Before the birth takes place, or before father and mother unite, there is a ceremony called  garbhādhāna-saṁskāra , which must be adopted. This  garbhādhāna-saṁskāra  is especially recommended for higher castes, especially the  brāhmaṇa  caste. It is said in the  śāstras  that if the  garbhādhāna-saṁskāra  is not practiced amongst the higher castes, the entire family becomes  śūdra . It is also stated that in this age of Kali, everyone is  śūdra  due to the absence of the  garbhādhāna-saṁskāra . This is the Vedic system. According to the  pāñcarātrika  system, however, even though everyone is a  śūdra  due to the absence of the  garbhādhāna-saṁskāra , if a person has but a little tendency to become Kṛṣṇa conscious, he should be given the chance to elevate himself to the transcendental platform of devotional service. Our Kṛṣṇa consciousness movement adopts this  pāñcarātrika-vidhi , as advised by Śrīla Sanātana Gosvāmī, who says:
yathā kāñcanatāṁ yāti kāṁsyaṁ rasa-vidhānataḥ