I think the main difference between Christianity and Islam is that the bible was written thousands of years ago, since Moises times, among all those years many different people by Holy Spirit inspiration predicted about the messiah, Jesus. The bible is maybe the most ancient book, and has the better backup regarding ancient manuscripts, being a copy of the book of Isaiah the oldest founded, a copy of 150 B.C in the dead sea. This is one of the books that has more prophecies about the messiah, the chapter 53 clearly talks about the sufferings of the God Servant, that is Jesus. Instead the Islam scriptures were written by Mahoma only, in the 600 A.C he just took the hebrew scriptures to create his own religion. Great post, God Bless you in the name of Jesus, the only name given to man to be saved.