What I prepose would kill off both Islame, Christianty and Judisme offbefore it grew is size

Muhammed didnt start his work until sometime in the years 600 something

Beside if muslims tried to force they way up here they would be kicked back so hard they would be sore for the next 1000 years, the Romans were kicked back by the Goths (not my sub-culture, but the people of old germeny) so you do you think they would have faired if they came across someone ever more b*tchy in combat