A Gnani can only show the way that much is the work of a Gnani.+

Sage Sankara: ~ "Though I wear these robes of a Sanyasin, it is only for the sake of bread." 

Sage Sankara states that the Knower of the Atman (i.e., a Gnani) "bears no outward mark of a holy man.  

Ashtavakra Samhita: ~ "The man of knowledge (Gnani), though living like an ordinary man is contrary to him and only those like him understand his state.

Upanishads: ~ Fools dwelling in darkness, but thinking they wise and erudite, go round and round, by various tortuous paths, like the blind led by the blind. (Upanishads Nikilanada - Ch II-5 P-14)

A person who realized the ultimate truth or Brahman will throw off his religious robe and his religious identity and becomes Avadhuta and live as he wishes. 

No one can teach anybody. The wisdom is hidden by the world in which you exist.  A Gnani can only show the way that much is the work of a Gnani. 

A Gnani only guides the seekers to apply their own reason and realize the truth, which is beyond the form, time and space. 

When the seeker learns to view and judge and reason the three states on the base of the Soul, the truth will start unfolding on its own. First, the seeker may find it difficult to use soulcentric reason but gradually it will become easy. 

The world is the same in the case of a Gnani and in the cause of the ignorant.  A Gnani has realized the world in which he exists is merely an illusion created out of the Soul, which is present in the form of the consciousness whereas the ignorant thinks the world, in which he exist is a reality. 

The look of an object will depend upon the medium through which the observer views it. In fact, our mental and intellectual conditions determine the object (three states), observed and experienced. The commoner viewing the world will see differently from a Gnani viewing the same world. Each one interprets the world that they see in terms of their existing knowledge. The commoner sees everything based on the ego, therefore, he sees the world in which he exists as a reality, whereas a Gnani sees everything as consciousness and he is fully aware of the fact that, there is no second thing exists other than the Soul or consciousness (subject). 

Thus, all the objective observation has to be bifurcated to realize the ultimate truth, which is hidden by the illusory form, time and space.

Remember:~

Only on the dualistic perspective, the changes take place. On the nondualistic perspective, there are no changes. Those who believe in the dualistic world as a reality and feel that knowledge changes from time to time but must realize their knowledge is limited to form, time, and space whereas Self-knowledge is the knowledge beyond the form, of time and space.

The change is possible only in ignorance. Ignorance is the cause of experiencing the world in which exists as a reality. Consciousness is the cause of the world in which we exist and it itself is uncaused.

The consciousness is ever changeless because it is a formless, timeless and spaceless existence. The world in which we exist is dependent on consciousness for its existence but the Soul, which is present in the form of consciousness, is independent. 

From the standpoint of the Soul, the Self, the world in which we exist is merely an illusion.

Only within the illusion, the changes take place, the illusory changes within the illusion is bound to be an illusion. 

In Advaitic reality, consciousness alone is real and eternal. Thus, the knowledge of the eternal will be always eternal. The intellectual knowledge based on the form, time and space is bound to change from time to time as science progresses in its dualistic inventions.:~Santthosh Kumaar