Muslims believe that the prophet muhammad was told the correct version of The Bible/religion.
Muslims beleive that the prophet muhammad was the last messenger by God, when it clearly says in The Bible that Jesus was the last messenger.
The only other advocate after Jesus Christ will be the spirit of truth.
The Islamic belief is a belief that cannot be substantiated. While today general religion can go back to the original scriptures, Muslims cannot go back to the original souce, as the prophet muhammad is dead.