To the choir obviously the answer to this question is a resounding no. To most others though faced with this question they are ready to concede that Islam has its origins in the light of day and so is likely true. The stories of Mohammed and his exploits seem so real to most people such that to even begin to show them it is as much a legend, and bad one at that, like other religious personages in history is a Herculean task. This belief is not based on fact rather it is one that has been properly built and passed on over time that it is likely considered true. At some time last year I wrote an article about Islam and its association with violence which in my opinion is supported by either the Koran or Hadiths that it is hard to separate Islam from violence even if you try so hard.
Many muslims are wont to say that Atheists fear to critique Islam. For one, muslims behave like cry babies albeit with guns so that when it is challenged they are up in arms defending the prophet god. One is left to wonder if their god is so powerless that it requires minions to fight for it all the time. It is appalling that they find no qualms killing people who disagree with their ignorance. They threaten anyone who dares leave the religion with death so much such that those Atheists in muslim countries live in fear for their lives and when they are able to write about it, they use several pseudonyms just so that family, friends and the community at large does not get to know.
There is no evidence for the Abrahamic god, the one muslims worship and so there is no way Mohammed or whoever the prophet was could have received a message from god. We have no evidence of ghosts, holy or otherwise and angels fallen or not so too none appeared to Mohammed. That aside however, Islam is as much a plagiarism of early Judaism, Christianity and Zoroaster beliefs that it is indeed funny to hear a muslim talk of purity of their cult.
There is an interesting book[ In the Shadow of the Sword] that took historian Tom Holland five years to compile on the history of Islam that is both informative and interesting and should be read first by all Muslims who care to think beyond what their imams tell them and then by everyone interested in religion.