Jerusalem in the Quran

Islam and Jesus/Issa according to the Quran.

"He [Jesus] said: 'I am indeed a servant of God. He has given me revelation and made me a prophet; He has made me blessed wheresoever I be; and He has enjoined on me prayer and charity as long as I live. He has made me kind to my mother, and not overbearing or miserable. So peace is on me the day I was born, the day that I die, and the day that I shall be raised up to life (again)!' Such was Jesus the son of Mary. It is a statement of truth, about which they (vainly) dispute. It is not befitting to (the majesty of) God that He should beget a son. Glory be to Him! When He determines a matter, He only says to it, 'Be,' and it is" (19:30-35).

Issa/ Jesus Son of Mary The Messenger

" Oh, you People of the Book! Commit not excesses in your religion, nor say of Allah anything but the truth. The Messiah, `Essa, the son of Maryam is no more than a Messenger of Allah, and His Word, which He bestowed upon Maryam, and a Spirit proceeding from Him: So believe in Allah and His Messengers. Say not "Three"-desist: It will be better for you: For Allah is one God, 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" (Qur'an 4:171)

The Quran is reminding the christians that God has and will always be one and not three or a trinity. God of Moses peace be with him and the commandments.
It also reminds all the readers that God ( Allah ) is the disposer of all affairs and that Issa/Jesus son of mary was Allah's messenger and the promised messiah sent to the Jews.