God's Spirit is a prevailing theme throughout the OT as well, very clearly defined as a spiritual presence, and having nothing to do with any single fallable man.
And while the claim that the Koran "uses all the words that Jesus used" sounds nice, Jesus and Mohammed had nothing in common, taught different things, lived different lives, and as a result, the Koran contradicts scripture frequently. If Mohammed didn't believe that Jesus was who He claimed to be, then Jesus was a liar, His whole ministry was based on lies, and He is certainly not worthy of Mohammed's, or any Muslim's, reverence.
Can you imagine? "Oh yes, he was a great man...of course you can't trust anything he said about himself to be the truth, but what a wonderful teacher and spiritual leader." Hardly sounds reasonable.
The Rabbis of the Jewish tribe in Yatrib (400 AD) prophesied that according to Torah a messenger would come for the Arabs.