Why do Christians not believe in Mohammed the Prophet, while so many Muslims believe in Jesus Christ?

because Christ mentions "I am the way the truth and the life, No one can come unto the Father except through me." we believe Christ was sent from God and therefore does not lie, so Christ saying No one would mean Mohammed also that he also would have to come to Christ in order to receive grace from God the father. Allso Paul mentions "For all have sinned and come short of the glory of God," which again would include Mohammed.and the prophets