ONCE somebody asked Bhagavan, “Why don’t you visit places and guide people on the right path as Sankara and some others did?”
Bhagavan: Merely being physically alive is itself an act of grace of Mahatmas.Even if they keep quiet, the vibrations set off by the power of their tapas spreads harmony and peace.
The question itself was inappropriate in the first place.Divine beings come into the world with a purpose and no distractions of their mission are desirable. The Maharshi’s abidance in the Self was intended to demonstrate the importance of experiential knowledge as distinct from mere bookish knowledge. The desire for experiential wisdom depends on one’s samskara and there is no use trying to inspire those who do not desire liberation.
Further, mouna-upadesa is best. That subtle power touches the subtle body of the seeker and influences his samskara. Instead of preferring this why look for speech
which is gross?
On another occasion a similar question was put to Bhagavan, to which he replied, “If you go and ask an electric fan to give light, it won’t give it. So is the case with an electric light if it is asked to provide breeze.” Each person had an allotted role to play, that was what Bhagavan meant.
Source: SRI RAMANA LEELA (A BIOGRAPHY OF BHAGAVAN SRI RAMANA MAHARSHI)
Telugu original Sri Krishna Bhikshu Edited and Translated by Pingali Surya Sundaram
My friend Prasad Chitta Garu has more detailed explanation regarding this subject.