Isa (عيسى ) is the Islamic name for Jesus, who is considered to be one of the Prophets of Islam in the Qu'ran. Christian Arabs refer to Jesus as Yasu' al-Masih (يسوع المسيح). Isa and Jesus are both most likely derived from the Latin Iesus, which in turn comes from the Greek Ἰησοῦς (Iēsoûs). The Greek form is a transliteration of the Aramaic name Yeshua (ישוע), a short form of Hebrew Yehoshua (יהושע). This is the name by which Moses called his successor as leader of the Israelites, known in English as Joshua; it means 'the Lord is salvation', or literally 'Yahweh saves'. A small minority hold that Isa is related to the biblical Esau, but this is less likely given the name's indisputably strong link with Joshua.
Muslims believe that Isa was sent down as a Prophet to be the Messiah. The Qu'ranic verse below explicitly calls him by this title, and also says that Allah sent word to Mary about it; it also calls him the Word of God. However, Muslims strongly disagree with the mainstream Christian belief mentioned in the Gospel of John that, as an embodiment of the divine logos, Jesus was hence divine himself, regarding it as a blasphemous denial of tawhid. (See below for relevant Qur'anic verses.)
Behold! the angels said: "O Mary, Allah gives you glad tidings of a Word from Him; his name will be the Messiah Jesus, the son of Mary, held in honor in this world and the Hereafter and of (the company of) those nearest to Allah.
(al-Qur'an 3:45)
The understanding of Jesus in Islam is very unlike the mainstream Jewish tradition, in which he is regarded as a false Messiah, and the Mandean religion (which views John the Baptist as the faithful one, and Jesus as a trickster).
Some liberal movements within Islam have tried to use the view that Jesus was originally a Jewish preacher as evidence that the divine message evolved over time from Judaism to Christianity and finally Islam.
Isa neither crucified nor killed
That they said (in boast) "We killed the Messiah Jesus the son of Mary, the Messenger of Allah"; - but they killed him not, nor crucified him, but so it was made to appear to them and those who differ therein are full of doubts, with no (certain) knowledge, but only conjecture to follow, for, of a surety they killed him not.
No, Allah raised him up unto Himself; and Allah is Exalted in Power, Wise.
(al-Qu'ran 4:157-158)
The passage above is claimed as support for the view that Isa was not killed or crucified, but instead was raised into Heaven and remains there awaiting the time appointed by Allah (God) to descend back to earth and live out his natural life.
Isa not the Son of God
O People of the Book, commit no excesses in your religion; nor say of Allah anything but the truth. The Messiah Jesus son of Mary was (no more than) a Messenger of Allah, and His Word, which He bestowed on Mary, and a Spirit proceeding from Him; so believe in Allah and His Messengers. Say not "Trinity": desist! It will be better for you: for Allah is One: Glory be to Him! (far exalted is He) above having a son. To Him belong all things in the heavens and on earth. And enough is Allah as a Disposer of affairs.
(al-Qu'ran 4:171)
Muslims do not believe Isa is Allah, nor was he the son of Allah; in this view they differ from Christians.
Muslims believe Isa will descend back to earth after ad-Dajjal (the False Messiah) appears.
Abu-Dawud Book 37, Number 4310:
Narrated Abu Hurayrah:
The Prophet (Muhammad) said: There is no prophet between me and him, that is, Jesus. He will descend (to the earth). When you see him, recognise him: a man of medium height, reddish fair, wearing two light yellow garments, looking as if drops were falling down from his head though it will not be wet. He will fight the people for the cause of Islam. He will break the cross, kill swine, and abolish jizyah. Allah will perish all religions except Islam. He will destroy the Antichrist and will live on the earth for forty years and then he will die. The Muslims will pray over him.
After he slays ad-Dajjal (the False Messiah) at the Gate of Hudd in Palestine, Muslims believe he will marry, die and be buried in the Masjid al Nabawi.