Religion is infinitely malleable if the culture around it changes sufficiently and customs are adapted accordingly.
Christianity was adapted in a thousand ways to turn from a tiny desert cult to an instrument of European power.
Starting by dropping food requirements to accommodate Helenic gentiles and Roman converts to the acceptance of divorce and Germanic winter solstice traditions. And don't get me started on commercialising the birthday of a man who said rich people don't go to heaven before assaulting bankers.
All you really need to do is break the flow of money and religious leaders from Saudi Arabia into local communities which cements Saudi fundamentalism around the globe in an effort to prevent integration into secular societies. Which causes rifts within communities, families and even individuals because the allure of freedom and conformity is incredibly strong when you see people around you who are not bound by the same rules and obligations as you are.
So you have natural attempts to lessen the pressure of the contradiction between the existing culture and the demands of religion over time. Which then collide with traditionalist and fundamentalist ideas causing the conflicts we see globally today. When Muslims murder each other or Western bystanders, this is a symptom of the incredible contradictions within the religion breaking open rifts much like they did in Christianity just before the wars of the Reformation. Thus happens not because the religion is never changing, but because it is tearing itself apart between tradition and modernity right now.