Good question, well Christianity and Islam share some stories like Abraham, Moses or Jacob but some how Islam got split from this branch and accepted the teaching's of Prophet Mohammed and after that Islam spread in most part of the world by power not by teaching like Christianity, I didn't say they never teach Islamic believes but most of the time they force people's to accept the religion countries like Turkey, Egypt, Sudan, Iran, Irak ... Were mostly forced to accept Islamic religion Jihad is also one factor, I don't believe that Jihad is fair but it's accepted in Islam as a good practice And in Christianity people's have to accept the religion only teaching otherwise forcing them is a sin but the opposite for Islam, ke bzu be teneshu this is my idea yaskefahuk neger kale yekerta