Who are they?
Islam teaches that the Holy Prophet (Muhammad) is a historical personage. The personality of Jesus is shrouded in mystery.
The life of Muhammad is well-documented (571 - 632 A.D.) although much of our knowledge depends on traditional accounts and biographies (Ibn Ishaq).
Christians, and essentially all historians, agree that someone called "Jesus" was a preacher from Galilee who lived in the first century A.D. The Quran accepts his historicity, "The Messiah, Jesus son of Mary, was only a messenger of Allah . . . So believe in Allah and His messengers" (4:An-Nisa:171).
More than eleven thousand persons have testified to the life and work of Muhammad. There is absolutely no contemporary evidence as to the life and work of Jesus.
Muhammad entered Mecca with 10,000 followers on January 11, 630 A.D., after his exile in Medinah. This is documented by contemporary sources. According to Bible's book of Acts, a contemporary source, 120 of the disciples of Jesus assembled immediately after his death (Acts 1:15).
The Apostle Paul, in his letters, claims to have seen Jesus (1Corinthians 9:1). The Bible documents that on at least eight separate occasions the Lord appeared to humans after his death (see our timeline of Jesus' ministry after his resurrection).
Muhammad gave a complete book to his followers which he declared was revealed to him by Allah and embodied in itself a perfect code of life. Jesus did not give a book of any description to his followers, and left the matter of religion entirely to their discretion.
The Koran depends entirely on Muhammad. For Jesus, a book already existed that bore witness to the truth. We call it the Old Testament. It was written by at least thirty people. The New Testament was written after the death of Jesus and comprises the writings of eight authors.
The Koran and the New Testament express opposite approaches to religion. The focus of Islam is on the "letter of the Law" versus true Christianity's focus on "the spirit of the Law."
Rules to live by
Muhammad gave an entirely new dispensation to the world. Jesus laid no claim to any such exalted position for himself, but told his followers to follow the same old Mosaic dispensation.
Muhammad's teaching was new to the Arabs, but he does not claim his dispensation is "entirely new", for it goes back to Abraham (2:Al-Baqarah:136). What Jesus proclaimed was how to see beyond the letter of the Mosaic Law into the nature of God and the life of the Spirit to which He is calling us. Jesus is reported to have made many claims, such as being "the way, the truth and the life" (John 14:6).
Muhammad taught the fundamental principles of his religion in unambiguous language and in unequivocal terms. There is therefore no dispute over them or no controversy about them in the Muslim world during all these thirteen centuries. Jesus knew nothing about the Trinity, the Incarnation, the Logos, the Transubstantiation, the Atonement, or the elaborate rituals of the Roman Church, and so on.
There are different Muslim "denominations," for example Sufism, but generally there is intolerance for divergent viewpoints. But there are aspects of popular Islam today which Muhammad would probably disagree with, such as the celebration of his birthday, Mawlid, and his veneration in branches of Sufism.
Jesus did not know of developments within Christianity after his time but would certainly disagree with many of the teachings (Pagan holidays, rejection of God's Sabbath and laws, promotion of the Trinity, etc.) supported by the vast majority of Protestants, Catholics and others who say they represent him.
The Holy Prophet is a human being just like ourselves and as such he can command our allegiance and our love. Jesus is perfect man plus perfect god and as such his personality has become quite an enigma. We cannot feel drawn towards him as he is not one of us. He belongs to quite a different species and as such he cannot serve as a model for us.
Anyone can be a role model. But what sort of role model? Muhammad lived a life of aggressive evangelism. Jesus lived a life of quiet service and was "tempted in all points like as we are, yet without sin" (Hebrews 4:15). We are to "walk as he walked."
Muhammad is the greatest exemplar for human beings. For twenty three long years, he lived and worked amongst us as an ordinary mortal and during this period he displayed so many phases of his humanity and so varied aspects of his sweet personality that men in all walks of life, from kings and rulers down to the man in the street, each one can find a definite pattern for his guidance in life ("The Ideal Character of the prophet" by M.S. Chaudry).
Jesus has absolutely no such beauty or excellence to his credit. He lived for barely three years after his ministry began and died ignominiously on the cross.
It is difficult to know what Muhammad was really like, for his life is surrounded with sympathetic legends. But obviously he has a certain physical appeal or none would follow him. Jesus indeed had "no form or comeliness that we should desire him" (Isaiah 53:2). His appeal is to the spiritual, not physical, side of our existence.
The Koran gives this exalted position to the Prophet. Allah says, "Verily, in the life of the Messenger of Allah there is a noble uswa (model) for you." Jesus makes no such claim.
The skeptic would note that, since Muhammad transmitted the Koran, his remarks about himself might be self-serving. The New Testament makes many claims about the exalted position of Jesus. Christ himself is careful to give all glory to God the Father.
The Holy Prophet "is the most successful of all the religious personalities of the world" (Encyclopedia Brittanica article on Muhammad). Jesus left his work unfinished owing to his sudden arrest and crucifixion (as believed and preached by the Christian Church).
Muhammad launched a highly successful international religion. Jesus calls his church "a little flock" (Luke 12:32). Christ continues his work to this very day, "And lo, I am with you always, even until the completion of the age" (Matthew 28:20).
Code of conduct
Muhammad gave a perfect code of life to his followers. Jesus left some portion of his teachings to be imparted by the Paraclete (Holy Spirit, John 14:16).
Muhammad did not exactly follow his own code, as he had, for example, at least twelve wives toward the end of his life. Christianity is a religion of continuing divine revelation in which believers are expected to "grow in grace and knowledge" (2Peter 3:18).
Mastery of the world
Muhammad wrought a mighty revolution and made Arabs master of the then civilized world. Jesus could not free his people, the Jews, from the yoke of the Romans.
The Arab empire was vast but where is it now? Jesus, unlike Muhammad, proclaimed a Kingdom that was not of this world (John 18:36). The beliefs taught by Christ ultimately conquered the Roman Empire. It should also be noted that, according to the CIA Factbook, more people in the world consider themselves Christian than being Muslim, Hindu, Buddhist or any other religious affiliation (2010 estimate).