What the heck is "pure Islam?"
Not to sound rude but you're not from the United States are you? Or English being your first language. If it is my apologies but the syntax of this response leads me to believe otherwise and if so, what country are you from?
Like I said people come and go in religion all the damn time this is not thread worthy. For every person that leaves Islam at least 20 more are born into it and at least 10 more convert to it.
This is what you have to look forward to and if trends like this beyond 2050 continue Islam will be the world's dominant religion: