Zakir, let me tell you something. At the past, I would always be scared to view any non-Muslim attacking Islam thinking that it would be very hard to refute, but as time passed, I have overcomed this, and now I can view any video freely and even refute them at the same moment. I realized that all their claims are the same, and weak. They are just blatant lies that are waiting for someone to expose them, so my advise to try to at least answer one claim by yourself, and this will show you how they always lie to misguide us.
