"I would say that we know specifically when it came on the scene, who wrote it, and what his life and his death was like.
Showing that allah is not the God of Christians and Jews is fairly simple. Showing the murderous side of mohammed and his movement is fairly simple."
Yes we can show these but I don't think we can separate the God of Islam with the Judeo/Christian one. From what I've read of the Koran, I think Mohammed was more than a little crazy. But I can say that about many early (especially) Catholic Saints, too. And Christians and Jews are not unstained with blood. Mohammed says he was inspired by God. It can't be proven that he wasn't. A whole lot of people believe him, not quite as many who are Christians, but if you subtract the "squishy" Christians (much of Europe) and the fringes (Moonies, JW's, SDA's, LDS's, etc.), the numbers become eerily similar.
Nice Sunday morning stuff.
I'm not particularly disposed to proving negatives, but it is provable that allah is not the same God as worshipped by Christians.
Can I prove that allah is not the true God?
I think that if I prove Mohammed used murder and mayhem to advance his religion and that Jesus rejected that in favor of others receiving faith because His "kingdom is not of this world." then I have highlighted the difference between the two.
Finally, Jesus claimed to be divine. His resurrection proves his point.
Mohammed was not divine. His death also proves Jesus' point.