Well, my research has suggested the same thing. Yet the Quran itself supposedly claims it is in Arabic, so that they can understand it. And that statement alone proves that Islam was not created for mankind, it was created for the Arabs who had nothing like what the Jews and Christians had. To me, it seems like Muhammad had some admiration for what they had, so he decided to create a version of it for his fellow Arabs. So he hijacked what they had, rewrote some things to suit his needs, and then leveled the charge of corruption against the things that he stole from so that his rewrites or changes could never be questioned. It's not very difficult to figure out.<quoted text>
Actually the Quran a book supposed to be written in pure arabic is filled of foreign words coming from Hebrew, Coptic, Syrian, Ethiopian, Persian, Greek and Indian etc.
But if you are an uneducated pagan Arab who had no idea of the religions Muhammad claimed he was completing, you will not know enough to see through the scam. But an overwhelming majority of Jews and Christians who knew the religions that Muhammad was claiming to complete could see through it right away.