Question: If you are saying that there is no world outside of me, then my friend doesn’t exist either, and he can say the same thing about me too. How is it possible to find out which of the two of us doesn’t exist? To whom am I referring when I call him a friend?
Answer: Actually, everything is an illusion until we begin to see the true world, not confused and distorted by our egoistic properties. Then a person will see that everyone makes up one single body, one soul.
From the Kabbalah Lesson in Russian 9/18/16