In this entire universe there is only one Teacher. Whenever someone is teaching, it is this Teacher that rises up inside of them and teaches through them. If there is no Inner Teacher, then the teacher is teaching from mind and not from Spiritual Truth. Their teachings come from ego and from books, but not from the Eternal Teacher that resides within.
Every great Master has told us that inside of everyone is our own Buddha Nature, some might call it our Inner Christ. Whatever we choose to call it, it resides deep inside of us where our consciousness is Pure and free of the distortion of karmic memories. Our Inner Christ is the true nature of our consciousness that some might also call our Higher Self. This Divine Presence is always there (even in the background) to guide us. In moments of inspiration this Divine Presence rises up inside of us and moves through us as the Great Teacher. The Ascended Masters call this the Mighty I AM Presence. It is our own Divine Presence!