Similar to Christianity - do you think that billions of people became muslim just voluntarily? No, Islam just like its sister Christianity was instructed by the prophets to conquer and destroy in their path for the god of Abraham. Here's a dufference between Christian narcissism and Muslim narcissism -

Christianity will convert heathens innovently and voluntarily it seems at first. If that fails, the Christians will use their military might to force heathens to be their flying monkeys. The Christian church will not preach that this is what they have done and what they do, instead insidiously assume that Christianity was always a religion of love and acceptance of heathens. There was no need for the use of military force to work its will. Christianity plays a lot of mind games, plays with the emotions and the intellect. 

Now, the narcissism of Islam is more in your face wreckless and upfront about its will. It does not preach in the disguise of love and white angels so much like Christianity - instead it is more blunt and honest about its intentions. This is the misunderstanding that many people have when comparing the two sisters - Islam is a more violent butcher religion and Christianity is more refined and loving. No they are both equally malignant and shit. Just because Christianity lies, veils its true intentions by putting a white wedding veil over its face does not make it more acceptable than Islam's unhidden ugly face. They are both destructive and have killed 10's of millions of people and forcefully converted 100's of millions. Christianity just does it in a different way than Islam. Both are haters of humanity conspiring to destroy the world.