RomeSweetHome,
I dont know why we Christians think that Muhammed had visions. FOR THE LAST TIME, HE DID NOT HAVE VISIONS. HE HAD VISITS FROM ANGEL GABRIEL 2400 times. and in the last revelations it completely stated that the Quran was completed.
And as for making miracles happen, a jew had once taken a fish to him because even though the fish was taken out of the water for a long time it wasn't dying and they weren't able to cut it. as soon as the fish was taken near Muhammad, the fish started to talk and it asked Muhammad to save it.
In the war of Badr, his 300 muslims were attacked by 10000 soldiers. when his people were dying he started prophesizing how middle east would be under control of a muslim nation. and at that time there were less than 300 muslims in the whole world. and just because he had said muslims would win, God sent 1000 angels there to help him and muslims were able to defend themselves. So as you can see, God had given Muhammad the power to always speak the truth about anytime and therefore make things happen just by saying them.