muhammad is not but a messenger. messengers have passed on before him. so if he was to die or be killed would you turn back on your heels ? and he who turns back on his heels will never harm allah at all but allah will reward the grateful.
وما محمد إلا رسول قد خلت من قبله الرسل أفإن مات أو قتل انقلبتم على أعقابكم ومن ينقلب على عقبيه فلن يضر الله شيئا وسيجزي الله الشاكرين