From a follower of NT Wright, here:
"The real Jesus must have been . . . consequential. Jesus left such an impact on the early Christians that they were willing to suffer and die for their testimony that he’d risen from the dead. A failed prophet or revolutionary might have attracted lasting admiration at best, but what could’ve happened to make devout monotheistic Jews worship this man after his death?"
For a false prophet in the opinion of Christians, Muhammad's message has built quite a following in the world despite being a younger religion in the history of humankind. It's laughable not to notice how successfully Islam has revolutionized vast swaths of the globe despite having no divine man who rose from the dead to worship, and how many have died in the cause of pressing its case on an unbelieving world in the past and in our own time, through war and through martyrdom.
Worldwide the 1.6 billion adherents of Islam face Mecca five times a day in something more than "lasting admiration", and now equal more than 70% of the global Christian population, while Hinduism's practitioners equal another 50%. Together the Muslims and Hindus outnumber the followers of Christ by over 20%.
Consider how many Muslims have martyred themselves in suicide bombings just in the period since 1982, as tracked by the Chicago Project on Security and Terrorism, here. There are in excess of 4,600 cases. Compare that with the number of Christians martyred until the time of Constantine, which my late teacher Robert M. Grant in a seminar on the apologists back in the day once put at no more than 5,000.