II Kings 6:14-17

Elisha could not literally see with his eyes all of these spirit beings that were out there on the mountain. But by faith, through the eyes of faith, because he knew God, because he was close to God, he understood that God was with Him always, and here was this tremendous army of angelic beings protecting His servant Elisha.

Whether that army was always there is a moot point. They may have been there simply because the Syrian army was there. It did not matter whether there was one or many; it was really an indication of God through Elisha, through the vision to this young man, that wherever God is, it is weighted in your favor. We have no need to fear the many who may come against us.