If G d's presence fills the universe, if there is no place where He is absent, and if He can be found wherever a person is, then why are angels required to bring a person's prayers up to G-d from chamber to chamber?
The answer is that G-d arranged things this way so that it would seem to a person that he is extremely distant, and would strive to get closer.
This can be understood by this story of the Baal Shem Tov. There was once a great and wise king who used optical illusions to give the impression that he had built walls, towers and gates around his palace. He then gave the order that whoever comes to him must go through the gates, and that treasures be scattered at all the gates.
Thus, some people who came to see the king found treasures at the first gate, took them and immediately turned around and went home, while others continued going through more gates until they could not carry anymore treasures, at which point they too turned around and went home.
However, the king's only son was not interested in the treasures, but only in reaching his father. He then realized that in reality, there were no walls at all separating him from his father, and that it was all an optical illusion.
The analogy of the story is that G-d hides Himself in various veils and walls. However, His glory fills the universe, and every single movement or thought is only Him. Thus, even all the angels and heavenly chambers were all created from His very essence, like the shell of an insect is an integral part of its body. Hence, there is absolutely no separation between man and G-d, and with this knowledge, all evildoers are dispersed.
from the teachings of the Baal Shem Tov