[TheLucyLee]

sir:
In the case of mantras, Guru has attained siddhis conferred by such mantra Devtas.
As far as Mahavakyam is concerned, Guru is one who has realized the Truth.

Guru means dispelling darkness or destroying avidya. It is ordained in the Upanishads
that a Guru must teach his student all that he has learnt without holding back anything.

HE also passes on HIS anubhuthi to the student. The lessons along with HIS grace
and anubhuthi lift the student. Otherwise you will sitting and chanting 'Aham
Brahmasmi' , and nothing will happen except some pain in your knees. A Guru is a
Must. Try to read the upanishads and understand what is said therein, in stead of
deriding them as Brokers.