AHC challenge: Middle East except for Persia and Arabia becomes majority Gnostic while Europe and North Africa become Nicene Christian as IOTL

The challenge is to have the Middle East except for Persia and Arabia become majority Gnostic by 600 while still having Europe and North Africa become majority Nicene Christian as in IOTL. Would that necessarily require the overthrow of Roman or later Byzantine authority? Or could some sort of compromise be made with Gnostics in order to maintain control over the Middle East? Also what would be the effects on Islam if the Middle East was Gnostic at the time of the Arab conquests? Or would Islam be butterflied away?
 
The challenge is to have the Middle East except for Persia and Arabia become majority Gnostic by 600 while still having Europe and North Africa become majority Nicene Christian as in IOTL. Would that necessarily require the overthrow of Roman or later Byzantine authority? Or could some sort of compromise be made with Gnostics in order to maintain control over the Middle East? Also what would be the effects on Islam if the Middle East was Gnostic at the time of the Arab conquests? Or would Islam be butterflied away?

Which Gnosticism? because there were many religious currents then that could be called "Gnostic".
 
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