Hey. :)
The people of the Scripture (Jews) ask you to cause a book to descend upon them from heaven. Indeed they asked Musa (Moses) for even greater than that, when they said: "Show us Allah in public," but they were struck with thunder clap and lightning for their wickedness. Then they worshipped the calf even after clear proofs, evidences, and signs had come to them. (Even) so We forgave them. And We gave Musa (Moses) a clear proof of authority.
And for their covenant, We raised over them the Mount and (on the other occasion) We said: "Enter the gate prostrating (or bowing) with humility;" and We commanded them: "Transgress not (by doing worldly works on) the Sabbath (Saturday)." And We took from them a firm covenant.
Because of their breaking the covenant, and of their rejecting the Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.) of Allah, and of their killing the Prophets unjustly, and of their saying: "Our hearts are wrapped (with coverings, i.e. we do not understand what the Messengers say)" - nay, Allah has set a seal upon their hearts because of their disbelief, so they believe not but a little.
And because of their (Jews) disbelief and uttering against Maryam (Mary ا ) a grave false charge (that she has committed illegal sexual intercourse);
: And because of their saying (in boast), "We killed Messiah 'Iesa (Jesus), son of Maryam (Mary), the Messenger of Allah," - but they killed him not, nor crucified him, but the resemblance of 'Iesa (Jesus) was put over another man (and they killed that man), and those who differ therein are full of doubts. They have no (certain) knowledge, they follow nothing but conjecture. For surely; they killed him not [i.e. 'Iesa (Jesus), son of Maryam (Mary) ]:
But Allah raised him ['Iesa (Jesus)] up (with his body and soul) unto Himself (and he is in the heavens). And Allah is Ever All*Powerful, All*Wise.
[Qur'an 4:153-158 -
Muhsin Khan translation]
Jesus was a messenger of Allaah/God, who was sent to the children of Isra'eel to call them to the worship of God without no associates, like all the previous prophets called to [i.e. Moses, David, Solomon, John the Baptist etc.]
Every prophet faced an enemy and opposition when he called people to worship God Alone, and Jesus faced similar situations. He was then imprisoned and although the people thought he was killed on the cross, he was taken up by God/Allaah Almighty to the heavens.
The people never killed him, rather there was someone else who was given the resemblance of Jesus (peace be upon him) [according to a scholarly opinion.] And this man was killed, hence this explains why alot of these people may have thought that they actually killed Jesus (peace be upon him.)
If you feel that it's unjust of God to allow someone to resemble Jesus (peace be upon him) and be killed, then you have to ask yourself why you believe that an honorable messenger of God, should be killed if he is guilty of no crime whatsoever?
Jesus was taught the gospel and the torah, and he called the people to worship God without no associates. All the previous prophets came with the same message, hence the same can be said about Jesus (peace be upon him.) According to christians, if one doesn't believe in the salvation - they can't be 'saved' - so what about the previous prophets, they had passed away before the 'salvation' took place, does that mean they can't gain no salvation either?!
According to christians, the earliest scripture after Jesus (peace be upon him) left this world, can only be linked back 350 years after he left this world. So how can we actually believe in its authenticity when
1) its not even in the language Jesus (peace be upon him) spoke [Aramaic],
2) It's 350yrs after Jesus left this world? We know that the Romans actually tried to get rid of the monotheistic aspects of the religion of Jesus [the true message of worshipping God Alone] because the Romans were polytheists themselves. Hence how can we believe in its authenticity? How can we accept if there is no solid proof for what Jesus (peace be upon him) actually said?
In islaam, we have both proof and faith and they both work hand in hand. So we have the Qur'an [the word of God revealed to His final servant & messenger, Muhammad (peace be upon him.)] Muhammad (peace be upon him) was illiterate and couldn't read or write, yet the Qur'an is a miracle and was written by his companions. The copy written by his companions is in the museum of turkey and any copy of the Qur'an you see today is the same, there aren't different 'versions' - rather we all have one copy and agree on its authenticity.
The Prophetic sayings are also a science where the whole chain of narrators of the Prophetic sayings are recorded, and the biographies of these people are written to verify the prophetic sayings authenticity. This is a whole science called the sciences of hadith.
The message revealed to Muhammad (peace be upon him) is the same message of all the previous prophets, to worship God Alone without no associates. If you wonder why God is Allaah in arabic, know that in spanish they call God - Dios, the French - Dieux, similarly in arabic it is Allaah, which even the christian arabs call God by.
We believe in God, His prophets, and the day when we will be brought back to life again and be judged on all that we do. Those who worship God without no associates will enter the eternal paradise through the Mercy of God, and those who reject God's worship, and associate partners with God [i.e. idols, other ways of life etc.] will be punished for turning away from the truth.
This has been the same message of all the prophets, and we will all die and be raised back to life. If God can create us out of nothing, its easy for Him to create us again, and He is Kind and Merciful to those who turn towards Him in obedience.
Just read the bible yourself and try to understand it to the above concepts, pray to God to guide you and us all to the true path. You'll come to know that God will guide, if we turn to Him in full sincerety. :)
If you got any questions, please ask. :)
Peace.