The Orbs of Light are four crystal balls that prove ones' status as a Light Warriors.
When the Light Warriors visited King Steve to apply for the Light Warrior's job. When King Steve's Assistant asked for the Orbs of Light as proof that they were the real Light Warriors, Black Mage realized that they did not have the real thing, quickly got a ladder to unscrew the light bulbs above them, and used them as the group's "Orbs of Light".
King Steve then noted they were "lukewarm with destiny" and was tricked into believing they were the real Orbs of Light.
The Real Light Warriors actually possessed the Orbs of Light, but King Steve kicked them out of his castle due to them not being "lukewarm with destiny".