[...] urged people to kill others, Jesus did not why is [...] followed by so many people?

Question from seeker:
Muhammad urged people to kill others, Jesus did not why is Muhammad a followed by so many people?

Answer
Never did he do it. What gives you that idea?

So-called false followers of enlightened souls have done it. So-called followers of Christ have destroyed nations after nations under the flag of Roman Catholics. Transgressed boundaries and tried to create empires in Asia, Africa, Australia and the Americas on the blood of Natives people of the land. Exploited and left those lands in poverty.

[BTW, I am not a Muslim, but a student of all religions.]

Christ and Mohammed are the maifestations of the same pure and benevolent being. Their messages were the same, no doubt in that: becoming better people and rising to our destiny of evolution.

They suffered the same tragedy of having their 'brands' taken to extremes by false followers. In case of Christ were Peter and Paul. In case of Prophet Mohd., it was his so-called friend who started the first runaway division of faith.

The true followers of Islam / Mohammed were Sufis (a word meaning 'pure'). Not the fundamentalist belligerents we see on TV. They don't even come close to the personality that Prophet Mohammed was.

Put yourself in His position and think, if you were gone and people twisted your words and made wars on those basis. So your contention is almost right, but not quite.

Another reason why many followers of Islam cropped up, especially in Africa was as follows: Africa, mostly ruled by French who proclaimed themselves to be 'Christians' and displayed all immoral character, repelled the African masses to drift away from Christianity. This was revealed in interviews done by H. H. Shri Mataji Nirmala Devi with African muslims, in an attempt to chart their exodus into Islam. That answers the numbers-part of your question.