Our belief concerning the real mission of Jesus, may peace be upon him, is that Jesus Christ was a Prophet sent to the Jews and believed in the One God. This is supported by his declaration that
First of all commandments is, 'Hear, O Israel: the Lord our God is One God'
and that Jesus was a Jewish prophet, he clearly stated that it is for 'the Jews Only' and "Go not into the way of the Gentiles" (Matt 10:5-6). Since the Gentiles were the 'non-Jews', Jesus came only for the Jews and made it clear to his followers not to go to the Gentiles.
Unfortunately, as with all the other prophets, the Jews rejected him as they did not want to hear his message. It was a message of peace and love, whereas they wanted a Messiah to lead them against the Roman rulers. It was a message of abiding by the law, but understanding the spirit of the law, which meant that he spoke against the Jewish leaders, and criticised them that they were misleading the Jews and not practising what they preached. But you can't just reject a prophet, you have to have a justifiable reason, so the Jewish leaders plotted against Jesus to get him crucified and thus proving him to be a false prophet, as "He that is hanged is accused of God" (Deuteronomy 21:23). How could a true prophet from God be accursed and go to hell, thus he must be false.
But the Holy Qur'an states:
And they [the Jews] planned and Allah also planned; and Allah is the best of planners
So we believe that Jesus did not die on the cross, instead Allah saved him and he then continued his message to the 'other sheep' (John 10:16) and travelled far and wide in search of the 'lost tribes of Israel', eventually dying at maybe the age of 120 years and being buried in Kashmir (his grave is still there).
There are around 30 proofs in the Holy Bible supporting our view, but in discussion with Christians you can sum it up in 3 points - before, just before and after crucifixion.