Islam owns atheism with a single verse

[Loaded dice]

Calling him an anti-Muslim proves nothing. 

Anti-Muslim implies they're biased against Islam, and therefore unreliable, got it ?

Refute his history WITH FACTS or STFU.

The history of Early Islam is impossible to build if you exclude Muslims' own sirah (bc they were the closest people to Muhammad), people like Spencer reject all Islamic sources and further dismiss the independent evidence of his existence(testimonies of other documented figures outside of Arabia, whatever long-standing effects his military career had, etc.), no wonder that he concludes that Muhammad never existed. Spencer deals with evidence unfairly, that's why we shouldn't listen to him.

It's true that there is a bias risk if one accepts Islamic sources, but Muslims dealt with their history very carefully by analyzing which reports are reliable and which aren't. To sum it up for you : Muslims were naturally closer to Muhammad than non-Muslims, therefore they heard more from Muhammad directly than anybody else, therefore their account of Muhammad is first-hand. Once we get rid of the fabrications, we get a reliable history of early islam.

Telling someone they are out of their mind just shows how ignorant, weak, and unprepared you are.

You're telling us that Muhammad never existed, you're just saying that for shock value, and because you only listen to one guy -a far right islamophobic journalist, nobody really claims this anymore, including atheists. Very few scholars of Islam dare saying that Muhammad never existed -and even these few only assert that he may have never existed, they learned to qualify their statements, unlike you. It's a minority view that has been criticized by the specialists of the field.