Calling Muhammad a Paedophile is just a cheap shot.
Take a good look through the bible and you'll see that many of god's most praised followers had similar habits. Taking wives so young that they would be put on a sexual offenders list these days. The usual argument is that back then no one knew that it was wrong to use children that way. Muhammad was no worse than any of them for that and should not be singled out.
The only difficulty for Christians and Muslims alike is that had there been a god there he could have told them. Plainly they had no help from any heavenly being or they'd have acted differently.
So not a prophet at all. Just some guy - who didn't know any better.