Upanayan (Yagnopavit) (Sacred thread initiation): ITS IMPORTANCE

In early age  son is initiated by the acharya with the sacred thread, known  as janoi or agnopavit. Amongst all the foregoing samskaras this is regarded as supreme. It is the dawn of a new life , hence dvija  -twice born. The child enters studentship and a life of perfect discipline which involves brahmacharya (celibacy).  He leaves the guardianship of his parents to be looked after by the acharya. This samskara is performed by Brahmins, Kshatriya s and Vaishyas, for both boys and  girls. Therefore, both the boy and girl received training in discipline, truthful living  and physical service. During the course of time this samskara ceased to be given to girls, who thus failed to be formally educated. T oday, the tradition of education underlying this samskara has died out. Upanayan only functions to bestow dvijatva to the son.Upa means 'near.' Nayan means 'to take (him) to,' i.e. to take the son to the teacher.
Like the parents, the acharya will mold th e student with love and patience into a man of character. He will inculcate in him the invaluable knowledge of the Vedas. This is the second meaning of Upanayan. Among all the cultural systems of the world, none have advocated such a lofty and stringent ideal for studentship than this Hindu  samskara. If a student sincerely observes this samskara, he will turn into a successful scholar. Added to this, during this period, he receives from the acharya, a strong background for the householder's life he will lat er enter. Today, it is obviously not feasible to stay at the acharya's house. But the next best equivalent is to enter a chhatralay -boarding school. The discipline involved  infuses in the student a fortitude generally not possible at home. Whereas students wear one janoi, householders could wear two; one for himself and one for his wife.The three strings of the janoi denote the three gunas -sattva (reality), rajas (passion), and tamas (darkness). They also remind the wearer that he has to pay off  the three debts he owes to the seers, ancestors and gods. The three strings are tied by a knot known as the brahmagranthi which symbolises Brahma (creator), Vishnu (sustainer) and Shiva  (leveller). One important significance of wearing the janoi is that the wearer would be constantly aware of the different deities which the threads represented. Therefore,  he would be vigilant prior to any action not in accordance with the Dharma Shastras.