Even for the sake of argument, if Muhammad didn't exist, then how did Islam become a world religion and then dominate many parts of the world without a leader guiding its people? Who did the Muslims learn from? Who or what caused the spread of Islam in such a short amount of time which can be directly linked to Muhammad's time and shortly after his death?
The thing is that Islam had already spread throughout many regions of the world before the death of Muhammad and he was also well-known at the time. There are biographies about the man written by both Muslim and non-Muslim historians with such an accuracy that they contain many specific dates and events which occurred during his lifetime such as where he was born, how he died, who were his wife and children, what battles he fought, what he said, where he slept, etc. He had a lineage and he had children as well as friends, family members, cousins, uncles, caliphs/successors, etc. They all lead back to a single man, i.e. Muhammad, and that's why I think that it is much more unlikely that the mention of this Muhammad over and over again was some "other" Muhammad and not the one being talked about every single time.
I didn't hear Robert Spencer address any of those important points about the existence of Muhammad. Instead, he only picked out some controversial events about Muhammad's life while taking certain things from Ibn Ishaq's book to support them and then magnifies them in a way just so that he can say that "maybe" Muhammad didn't exist. Just "maybe," but nothing else beyond that.
Also, see: Muhammad: His Life Based on the Earliest Sources (by Martin Lings)
The thing is that Islam had already spread throughout many regions of the world before the death of Muhammad and he was also well-known at the time. There are biographies about the man written by both Muslim and non-Muslim historians with such an accuracy that they contain many specific dates and events which occurred during his lifetime such as where he was born, how he died, who were his wife and children, what battles he fought, what he said, where he slept, etc. He had a lineage and he had children as well as friends, family members, cousins, uncles, caliphs/successors, etc. They all lead back to a single man, i.e. Muhammad, and that's why I think that it is much more unlikely that the mention of this Muhammad over and over again was some "other" Muhammad and not the one being talked about every single time.
I didn't hear Robert Spencer address any of those important points about the existence of Muhammad. Instead, he only picked out some controversial events about Muhammad's life while taking certain things from Ibn Ishaq's book to support them and then magnifies them in a way just so that he can say that "maybe" Muhammad didn't exist. Just "maybe," but nothing else beyond that.
Also, see: Muhammad: His Life Based on the Earliest Sources (by Martin Lings)
