"...read how arabic and islam spread through north africa and the levant. The people there didn't wake up one day and start speaking arabic and praying to a different god than the one they had before..."

Hope you have read enough history already...the other day you had mentioned the same example in one of the threads and i had given you a link to read (which probably you didn't and again you are raising the same issue)

No religion can spread through force...people can be forced to worship different god publicly - but can they be forced to do the same in the privacy of their homes ??

Also, would be interested to know from which part of the world you belong because it is strange to know how your great grand parents remained unaffected by the muslim armies which were invading countries and forcing people across the globe to convert to islam. -:)