According to the Koran and the Sunna (the words and acts of Muhammad), the Koran existed before the beginning of the world and lies on an immense emerald table at Allah’s side. It was dictated by Allah through the Angel Gabriel piece by piece to Muhammad over the last 23 years of the Prophet’s life. Faithful Muslims believe the Koran is absolutely authoritative, and the Sunna, which is often clearer and more complete than the Koran, is also held in sacred regard. To Muslims, the Koran is unchanging truth. To the Western observer, however, it often seems inconsistent. Muslim scholars and clergy explain that Allah can change his mind and that his revelations in the Koran were progressive. This is the reason for the Islamic doctrine of Abrogation—whatever Allah said last either abrogates or overshadows contradicted earlier verses. This is often used for situational ethics according to whether Muslims are in a strong or weak position in their continuing Jihad against all non-Muslims. Since Muhammad’s career became increasingly devoted to war against non-Muslims, this almost always gives later “war-verses” precedence over peaceful verses, but the peaceful verses may be used when in a weak military or political circumstance or to deceive non-Muslims. Islam thus has a dualistic ethical system rather than a unitary ethical system. The Golden Rule is a unitary ethical concept that has the same standards of fairness for everyone. Islam’s dualistic ethical system allows non-Muslims to be treated with less human regard than Muslims.
Non-Muslim religious scholars recognize that the Koran seems to be based on several sources. There seems to be a thin but continuous stream of Abrahamic monotheistic traditions with many power and authority characteristics of an almighty deity. After all, many Jews and most Arabs belong to the same Y-DNA genetic family, as we would expect from reading Genesis. In addition to numerous heretical stories about Jesus common among unorthodox Christian sects in the Middle East in Muhammad’s time (570-632 AD), Rev. W. St. Clair-Tisdall, writing circa 1901, also found considerable Persian (Zoroastrian) influence, especially the description of paradise in chapters 55 and 56 of the Koran. He also noted Sabean (as in Queen of Sheba), Egyptian, and Hindu influences. Such scholarship would probably be difficult in today’s politically correct university environments. Muhammad had traveled extensively as a caravan merchant and was obviously interested in religion. He also had a Christian sex-slave, Mary the Coptic Egyptian, one of his favorites, who could have related some stories to him. Another difficulty with the Koran is that the third Caliph, Uthman Ibn Affan, forcibly revised and standardized the Koran and destroyed all unstandardized copies, making himself an enormously important gatekeeper.
The Koran gives Jesus (Isa in Arabic) an exalted position as one of the mightiest messengers of Allah. He performed miracles, healed the sick, raised the dead, and is recognized as a righteous prophet, but he was not recognized as the divine Son of God or a Savior who could forgive sins.
In fact, attributing his fatherhood to Allah and the concept of the Christian Trinity are blasphemy (Koran 5:75) punishable by death in Islam. He is primarily a prophet to the Jews to point out the later coming of Muhammad, the supreme prophet of Allah (Koran 61:6).
The Muslim Jesus was born of a virgin, Mary, but Mary is called the sister of Aaron (Koran 19: 29 and 66:12), a historical error of 1200 to 1400 years. As a child, Jesus is said to speak from his cradle, telling learned men that he was a prophet. According to chapters 3 and 5 of the Koran, as a boy, Jesus made clay pigeons and breathed life into them and let them fly away. Also according to the Koran, Jesus was a faithful Muslim and did not suffer and die on the cross or save anyone from their sins (Koran 4:157) but was taken up to paradise to await the Last Days, when he would return to rebuke Christians, who claim that He is God and Savior. He will assist the Mahdi, the Muslim Messiah, who will defeat and annihilate the Jews and their allies and impose Islamic Law (Sharia) on the world. [Reference to Hadiths: Abu Muslim (37-4310); Bukari (3-46-656); Sharia: Al-Misri, Reliance of the Traveller (O9.8, p. 603 on Jihad; Koran 4:159]
There are four major Biblical interpretations of Christian eschatology that differ in timing and details, but in the simplest, Jesus returns to defeat the anti-Christ and his forces and bring everlasting life, peace, and justice to those whose faith has been placed in Him. The Islamic Mahdi is a human Messiah in absolute conflict with the Biblical Jesus. The Muslim Jesus (Isa) plays a subordinate role as a military leader and religious reformer-prophet assisting the Mahdi in his final Jihad against believing Christians and Jews.
So, the Jesus (Isa) of the Koran and Sunna is a figure imitating but strongly oppositional to the Jesus of Christian Scripture and faith.