Ultimately, there is only one real Master for every spiritual seeker, and that is his own divine Overself. The human teacher may assist him to the extent of giving him a temporary emotional uplift or a temporary intellectual perception, but he cannot bestow permanent divine consciousness on another individual. All that the teacher can do is to point out the way through the labyrinth; the journey must be made by the seeker himself. For example, an individual living alone on a desert island could travel through all the stages of the Quest and attain the highest realization even though he had no visible teacher. The Overself will give him all the guidance and help he needs. However, he is likely to mistakenly believe that his own ego is making the progress.
-- Notebooks Category 1: Overview of the Quest > Chapter 3: Independent Path > # 102