Transmission of truths

The esoteric content of scriptural knowledge is eternal and unchanging and the Bhagavadh Gita exemplifies the way in which this knowledge has been transmitted in the oral tradition when Lord Krishna becomes a preceptor (Guru , teacher ) to enlighten Arjuna and humanity.In the Upanishads , transmission of the message is important and sages have been directly enlightened about spiritual truths and this knowledge has been handed down from preceptor to disciple.
Lord Krishna tells Arjuna that the truths He now instructs were orginally taught by him to the Sun God , who in turn taught it to Manu and Manu taught Ikshvaku. But in course of time this tradition that was maintained from preceptor to disciple had been lost.
Arjuna asked Lord Krishna how He could have taught this knowledge long back to Sun God. The Lord says that He has been born into this world several times. Likewise , Arjuna also has been born many times. But while the Lord knows the secrets of the births of all beings , Arjuna is aware of this present birth alone. Moreover , He states that though He is without begining or end, He is born time and again out of His Sankalpa and Maya.
In contemporary times Sri Ramakrishna was a preceptor who had realised God and only one who has done so can certify and guarantee the credibility of the spiritual message.
A preceptor's ability to communicate effectively depends on his spiritual strength derived from direct perception rather than logic or reason that can eclipse spiritual conviction.
The basis of this beleif is the awareness of the presence of the immortal and the everlasting against the background of whatever is ephemeral and fast fading.
Reference from : " The Hindu " newspaper and internet sources