“The guru is Brahma, Vishnu and Mahesh (Shiva), veneration to the Guru who is Parabrahman manifest.” The second line of the couplet does not literally mean that the Guru becomes Parabrahman – God, rather he is venerated as if God is manifesting through him.
This is subtly illustrated by another famous verse known to all Hindus:
The Guru and Govind -God, are present before me, to whom shall I bow down first? Glory to the Guru since he showed me Govind.
Apart from guiding the aspirant on the path to God-realization, the Guru throws light on the profound meanings of the vast array of scriptural knowledge. Hence the Mundaka Upanishad calls such a Guru “Shrotriya” – knower of the true meanings of the scriptures.
Adi Shankaracharya forbids an aspirant in endeavoring to decipher the meanings without a Guru. In his commentary on a Mantra (1/2/13) of the Mundaka Upanishad, he says: “Even if one possesses knowledge of the scriptures, he should not attempt to delve into their meanings by himself. He should obtain the knowledge of Brahman only through the Guru.”
In their treatises, other Acharyas, such as Ramanuj and Nimbark have considered the Guru mandatory in God-realization.
