The mustadi practice a form of monolatrism – that is they worship one god, but understand and accept that other people worship other gods as well.
Their god is a powerful and benevolent god who they refer to in a variety of ways: The One of Us and The Great Beneficence are the most popular. They do not understand their god to be like them. Instead it is described as eternal, omnipotent, and ultimate good. It is never depicted in an anthropomorphic way, but as power mixed within mystery: like a smoking brazier, or a tree obscured by a blizzard.
With the loss of their warren to Iontia there has been talk of a messianic prophecy. This anointed of the mustadi will unite them and lead them back to their lost warren, reclaiming the ancient city and ushering in a mustadi renaissance.
They offer sacrifice to this god in a variety of ways. Typically it is the first fruits of the harvest, game, and pearls. it is dependent on both season and geographic availability.
There has been talk of a zealot movement within the mustadi who revere the messianic prophecy. Some claim that by sacrificing Iontians it will appease The One of Us and hasten his sending of the messiah.