The friends of the twice-born families are those who are born in the families of brāhmaṇas, kṣatriyas and vaiśyas, or the spiritually cultured families, but who themselves are not equal to their forefathers. Such descendants are not recognized as such, for want of purificatory achievements. The purificatory activities begin even before the birth of a child, and the seed-giving reformatory process is called Garbhādhāna-saṁskāra. One who has not undergone such Garbhādhāna-saṁskāra, or spiritual family planning, is not accepted as being of an actual twice-born family. The Garbhādhāna-saṁskāra is followed by other purificatory processes, out of which the sacred thread ceremony is one. This is performed at the time of spiritual initiation. After this particular saṁskāra, one is rightly called twice-born. One birth is calculated during the seed-giving saṁskāra, and the second birth is calculated at the time of spiritual initiation. One who has been able to undergo such important saṁskāras can be called a bona fide twice-born.
(Srimad Bhagavatam--------1:4:25--------purport).

(Nārada Muni had asked how one could ignorantly defy one's own father. The Haryaśvas understood the meaning of this question.) One must accept the original instructions of the śāstra. According to Vedic civilization, one is offered a sacred thread as a sign of second birth. One takes his second birth by dint of having received instructions in the śāstra from a bona fide spiritual master. Therefore, śāstra, scripture, is the real father. All the śāstras instruct that one should end his material way of life. If one does not know the purpose of the father's orders, the śāstras, he is ignorant. The words of a material father who endeavors to engage his son in material activities are not the real instructions of the father.
Bhagavad-gītā (16.7) says, pravṛttiṁ ca nivṛttiṁ ca janā na vidur āsurāḥ: demons, who are less than human beings but are not called animals, do not know the meaning of pravṛtti and nivṛtti, work to be done and work not to be done. In the material world, every living entity has a desire to lord it over the material world as much as possible. This is called pravṛtti-mārga. All the śāstras, however, advise nivṛtti-mārga, or release from the materialistic way of life. Apart from the śāstras of the Vedic civilization, which is the oldest of the world, other śāstras agree on this point. For example, in the Buddhist śāstras Lord Buddha advises that one achieve nirvāṇa by giving up the materialistic way of life. In the Bible, which is also śāstra, one will find the same advice: one should cease materialistic life and return to the kingdom of God. In any śāstra one may examine, especially the Vedic śāstra, the same advice is given: one should give up his materialistic life and return to his original, spiritual life. Śaṅkarācārya also propounds the same conclusion. Brahma satyaṁ jagan mithyā: this material world or materialistic life is simply illusion, and therefore one should stop his illusory activities and come to the platform of Brahman.
(Srimad Bhagavatam--------6:5:20---------translation and purport).

When Lord Brahmā was perplexed about how to construct the material manifestations in the universe and went down within the water to find out the means and the source of his lotus seat, he heard the word tapa vibrated twice. Taking the path of tapa is the second birth of the desiring disciple. The word upāśṛṇot is very significant. It is similar to upanayana, or bringing the disciple nearer to the spiritual master for the path of tapa. So Brahmājī was thus initiated by Lord Kṛṣṇa, and this fact is corroborated by Brahmājī himself in his book the Brahma-saṁhitā. In the Brahma-saṁhitā Lord Brahmā has sung in every verse govindam ādi-puruṣaṁ tam ahaṁ bhajāmi. Thus Brahmā was initiated by the Kṛṣṇa mantra, by Lord Kṛṣṇa Himself, and thus he became a Vaiṣṇava, or a devotee of the Lord, before he was able to construct the huge universe.
(Srimad Bhagavatam--------2:9:6--------purport).

Two words in this verse are very important; one word is pitari, and another word is guroḥ. The son or disciple should accept the words of his spiritual master and father without hesitation. Whatever the father and the spiritual master order should be taken without argument: "Yes." There should be no instance in which the disciple or the son says, "This is not correct. I cannot carry it out." When he says that, he is fallen. The father and the spiritual master are on the same platform because a spiritual master is the second father. The higher classes are called dvija, twice-born. Whenever there is a question of birth, there must be a father. The first birth is made possible by the actual father, and the second birth is made possible by the spiritual master. Sometimes the father and the spiritual master may be the same man, and sometimes they are different men. In any case, the order of the father or the order of the spiritual master must be carried out without hesitation, with an immediate yes. There should be no argument. That is real service to the father and to the spiritual master.
(Srimad Bhagavatam--------3:24:13--------purport).

After this, Vasudeva had his sons initiated by sacred thread as the token of second birth, which is essential for the higher castes of human society. Vasudeva called for his family priest and learned brāhmaṇas, and the sacred thread ceremony of Kṛṣṇa and Balarāma was duly performed. During this ceremony, Vasudeva gave various ornaments in charity to the brāhmaṇas and endowed them with cows decorated with silken cloths and golden ornaments. Then Vasudeva remembered the cows he had wanted to give in charity to the brāhmaṇas after the birth of Kṛṣṇa and Balarāma. But being imprisoned by Kaṁsa at that time, Vasudeva had been able to do so only within his mind, for Kaṁsa had stolen all his cows. With the death of Kaṁsa his cows were released, and now Vasudeva gave the actual cows to the brāhmaṇas. Then Balarāma and Kṛṣṇa were duly initiated with the sacred thread ceremony, and They repeated the chanting of the Gāyatrī mantra. The Gāyatrī mantra is offered to disciples after the sacred thread ceremony, and Balarāma and Kṛṣṇa properly discharged the duties of chanting this mantra. Anyone who executes the chanting of this mantra has to abide by certain principles and vows. Although Balarāma and Kṛṣṇa are transcendental personalities, They strictly followed the regulative principles. They were initiated by Their family priest, Gargācārya, usually known as Garga Muni, the ācārya of the Yadu dynasty. According to Vedic culture, every respectable family has an ācārya, or spiritual master. One is not considered a perfectly cultured man without being initiated and trained by an ācārya. It is said, therefore, that one who has approached an ācārya is actually in perfect knowledge. Lord Kṛṣṇa and Lord Balarāma are the Supreme Personality of Godhead, the master of all education and knowledge. There was no need for Them to accept a spiritual master, or ācārya, yet for the instruction of ordinary men They also accepted a spiritual master for advancement in spiritual knowledge.
(Krsna Book).

Śrīla Sūta Gosvāmī said: Let me offer my respectful obeisances unto that great sage (Śukadeva Gosvāmī) who can enter the hearts of all. When he went away to take up the renounced order of life (sannyāsa), leaving home without undergoing reformation by the sacred thread or the ceremonies observed by the higher castes, his father, Vyāsadeva, fearing separation from him, cried out, "O my son!" Indeed, only the trees, which were absorbed in the same feelings of separation, echoed in response to the begrieved father.
The institution of varṇa and āśrama prescribes many regulative duties to be observed by its followers. Such duties enjoin that a candidate willing to study the Vedas must approach a bona fide spiritual master and request acceptance as his disciple. The sacred thread is the sign of those who are competent to study the Vedas from the ācārya, or the bona fide spiritual master. Śrī Śukadeva Gosvāmī did not undergo such purificatory ceremonies because he was a liberated soul from his very birth.
Generally, a man is born as an ordinary being, and by the purificatory processes he is born for the second time. When he sees a new light and seeks direction for spiritual progress, he approaches a spiritual master for instruction in the Vedas. The spiritual master accepts only the sincere inquirer as his disciple and gives him the sacred thread. In this way a man becomes twice-born, or a dvija. After qualifying as a dvija one may study the Vedas, and after becoming well versed in the Vedas one becomes a vipra. A vipra, or a qualified brāhmaṇa, thus realizes the Absolute and makes further progress in spiritual life until he reaches the Vaiṣṇava stage. The Vaiṣṇava stage is the postgraduate status of a brāhmaṇa. A progressive brāhmaṇa must necessarily become a Vaiṣṇava, for a Vaiṣṇava is a self-realized, learned brāhmaṇa.
Śrīla Śukadeva Gosvāmī was a Vaiṣṇava from the beginning; therefore, there was no need for him to undergo all the processes of the varṇāśrama institution. Ultimately the aim of varṇāśrama-dharma is to turn a crude man into a pure devotee of the Lord, or a Vaiṣṇava. Anyone, therefore, who becomes a Vaiṣṇava accepted by the first-class Vaiṣṇava, or uttama-adhikārī Vaiṣṇava, is already considered a brāhmaṇa, regardless of his birth due to his past deeds. Śrī Caitanya Mahāprabhu accepted this principle and recognized Śrīla Haridāsa Ṭhākura as the ācārya of the holy name, although Ṭhākura Haridāsa appeared in a Mohammedan family. In conclusion, Śrīla Śukadeva Gosvāmī was born a Vaiṣṇava, and, therefore, brahminism was included in him. He did not have to undergo any ceremonies. Any lowborn person—be he a Kirāta, Hūṇa, Āndhra, Pulinda, Pulkaśa, Ābhīra, Śumbha, Yavana, Khasa or even lower—can be delivered to the highest transcendental position by the mercy of Vaiṣṇavas. Śrīla Śukadeva Gosvāmī was the instructing spiritual master of Śrī Sūta Gosvāmī, who therefore offers his respectful obeisances unto Śrīla Śukadeva Gosvāmī before he begins his answers to the questions of the sages at Naimiṣāraṇya.
(Srimad Bhagavatam--------1:2:2---------translation and purport).

Out of compassion, the great sage thought it wise that this would enable men to achieve the ultimate goal of life. Thus he compiled the great historical narration called the Mahābhārata for women, laborers and friends of the twice-born.
The friends of the twice-born families are those who are born in the families of brāhmaṇas, kṣatriyas and vaiśyas, or the spiritually cultured families, but who themselves are not equal to their forefathers. Such descendants are not recognized as such, for want of purificatory achievements. The purificatory activities begin even before the birth of a child, and the seed-giving reformatory process is called Garbhādhāna-saṁskāra. One who has not undergone such Garbhādhāna-saṁskāra, or spiritual family planning, is not accepted as being of an actual twice-born family. The Garbhādhāna-saṁskāra is followed by other purificatory processes, out of which the sacred thread ceremony is one. This is performed at the time of spiritual initiation. After this particular saṁskāra, one is rightly called twice-born. One birth is calculated during the seed-giving saṁskāra, and the second birth is calculated at the time of spiritual initiation. One who has been able to undergo such important saṁskāras can be called a bona fide twice-born.
If the father and the mother do not undertake the process of spiritual family planning and simply beget children out of passion only, their children are called dvija-bandhus. These dvija-bandhus are certainly not as intelligent as the children of the regular twice-born families. The dvija-bandhus are classified with the śūdras and the woman class, who are by nature less intelligent. The śūdras and the woman class do not have to undergo any saṁskāra save and except the ceremony of marriage.
The less intelligent classes of men, namely women, śūdras and unqualified sons of the higher castes, are devoid of necessary qualifications to understand the purpose of the transcendental Vedas. For them the Mahābhārata was prepared. The purpose of the Mahābhārata is to administer the purpose of the Vedas, and therefore within the Mahābhārata is placed the Bhagavad-gītā, the summary Veda. The less intelligent are more interested in stories than in philosophy, and therefore the philosophy of the Vedas is included within the Mahābhārata in the form of the Bhagavad-gītā, spoken by Lord Śrī Kṛṣṇa. Vyāsadeva and Lord Kṛṣṇa are both on the transcendental plane, and therefore they collaborated in doing good to the fallen souls of this age. The Bhagavad-gītā is the essence of all Vedic knowledge. It is the first book of spiritual values, as the Upaniṣads are. The Vedānta philosophy is the subject matter for study by the spiritual graduates. Only the post-graduate spiritual student can enter into the spiritual or devotional service of the Lord. It is a great science, and the great professor is the Lord Himself in the form of Lord Śrī Caitanya Mahāprabhu. And persons who are empowered by Him can initiate others in the transcendental loving service of the Lord.
(Srimad Bhagavatam--------1:4:25---------translation and purport).

While thus engaged in thinking, in the water, Brahmājī heard twice from nearby two syllables joined together. One of the syllables was taken from the sixteenth and the other from the twenty-first of the sparśa alphabets, and both joined to become the wealth of the renounced order of life.
In Sanskrit language, the consonant alphabets are divided into two divisions, namely the sparśa-varṇas and the tālavya-varṇas. From ka to ma the letters are known as the sparśa-varṇas, and the sixteenth of the group is called ta, whereas the twenty-first letter is called pa. So when they are joined together, the word tapa, or penance, is constructed. This penance is the beauty and wealth of the brāhmaṇas and the renounced order of life. According to Bhāgavata philosophy, every human being is meant simply for this tapa and for no other business, because by penance only can one realize his self; and self-realization, not sense gratification, is the business of human life. This tapa, or penance, was begun from the very beginning of the creation, and it was first adopted by the supreme spiritual master, Lord Brahmā. By tapasya only can one get the profit of human life, and not by a polished civilization of animal life. The animal does not know anything except sense gratification in the jurisdiction of eat, drink, be merry and enjoy. But the human being is made to undergo tapasya for going back to Godhead, back home.
(Srimad Bhagavatam--------2:9:6---------translation and purport).

"One should know the ācārya as Myself and never disrespect him in any way. One should not envy him, thinking him an ordinary man, for he is the representative of all the demigods."
This is a verse from Śrīmad-Bhāgavatam (11.17.27) spoken by Lord Kṛṣṇa when He was questioned by Uddhava regarding the four social and spiritual orders of society. The Lord was specifically instructing how a brahmacārī should behave under the care of a spiritual master. A spiritual master is not an enjoyer of facilities offered by his disciples. He is like a parent. Without the attentive service of his parents, a child cannot grow to manhood; similarly, without the care of the spiritual master one cannot rise to the plane of transcendental service.
The spiritual master is also called ācārya, or a transcendental professor of spiritual science. The Manu-saṁhitā (2.140) explains the duties of an ācārya, describing that a bona fide spiritual master accepts charge of disciples, teaches them the Vedic knowledge with all its intricacies, and gives them their second birth. The ceremony performed to initiate a disciple into the study of spiritual science is called upanīti, or the function that brings one nearer to the spiritual master. One who cannot be brought nearer to a spiritual master cannot have a sacred thread, and thus he is indicated to be a śūdra. The sacred thread on the body of a brāhmaṇa, kṣatriya or vaiśya is a symbol of initiation by the spiritual master; it is worth nothing if worn merely to boast of high parentage. The duty of the spiritual master is to initiate a disciple with the sacred thread ceremony, and after this saṁskāra, or purificatory process, the spiritual master actually begins to teach the disciple about the Vedas. A person born a śūdra is not barred from such spiritual initiation, provided he is approved by the spiritual master, who is duly authorized to award a disciple the right to be a brāhmaṇa if he finds him perfectly qualified. In the Vāyu Purāṇa an ācārya is defined as one who knows the import of all Vedic literatures, abides by their rules and regulations, and teaches his disciples to act in the same way.
(Sri Caitanya Caritamrta--------1:1:46--------translation and purport).

Sir, we belong to the lowest class of men, and our associates and employment are also of the lowest type. Therefore we cannot introduce ourselves to You. We feel very much ashamed, standing here before You.
Although the two brothers, Rūpa and Sanātana (at that time Dabira Khāsa and Sākara Mallika), presented themselves as being born in a low family, they nonetheless belonged to a most respectable brāhmaṇa family that was originally from Karṇāṭa. Thus they actually belonged to the brāhmaṇa caste. Unfortunately, because of being associated with the Muslim governmental service, their customs and behavior resembled those of the Muslims. Therefore they presented themselves as nīca-jāti. The word jāti means birth. According to śāstra, there are three kinds of birth. The first birth is from the womb of the mother, the second birth is the acceptance of the reformatory method, and the third birth is acceptance by the spiritual master (initiation). One becomes abominable by adopting an abominable profession or by associating with people who are naturally abominable. Rūpa and Sanātana, as Dabira Khāsa and Sākara Mallika, associated with Muslims, who were naturally opposed to brahminical culture and cow protection. In Śrīmad-Bhāgavatam (Seventh Canto) it is stated that every person belongs to a certain classification. A person is identifiable by the special symptoms mentioned in the śāstras. By one's symptoms, one is known to belong to a certain caste. Both Dabira Khāsa and Sākara Mallika belonged to the brāhmaṇa caste, but because they were employed by Muslims, their original habits degenerated into those of the Muslim community. Since the symptoms of brahminical culture were almost nil, they identified themselves with the lowest caste. In the Bhakti-ratnākara it is clearly stated that because Sākara Mallika and Dabira Khāsa associated with lower-class men, they introduced themselves as belonging to the lower classes. Actually, however, they had been born in respectable brāhmaṇa families.
(Sri Caitanya Caritamrta--------2:1:189--------translation and purport).

The spiritual master is also called ācārya, or a transcendental professor of spiritual science. The Manu-saṁhitā (2.140) explains the duties of an ācārya, describing that a bona fide spiritual master accepts charge of disciples, teaches them the Vedic knowledge with all its intricacies, and gives them their second birth. The ceremony performed to initiate a disciple into the study of spiritual science is called upanīti, or the function that brings one nearer to the spiritual master. One who cannot be brought nearer to a spiritual master cannot have a sacred thread, and thus he is indicated to be a śūdra. The sacred thread on the body of a brāhmaṇa, kṣatriya or vaiśya is a symbol of initiation by the spiritual master; it is worth nothing if worn merely to boast of high parentage. The duty of the spiritual master is to initiate a disciple with the sacred thread ceremony, and after this saṁskāra, or purificatory process, the spiritual master actually begins to teach the disciple about the Vedas. A person born a śūdra is not barred from such spiritual initiation, provided he is approved by the spiritual master, who is duly authorized to award a disciple the right to be a brāhmaṇa if he finds him perfectly qualified. In the Vāyu Purāṇa an ācārya is defined as one who knows the import of all Vedic literatures, abides by their rules and regulations, and teaches his disciples to act in the same way.
(Sri Caitanya Caritamrta--------1:1:46------purport).