Jesus The Universal Saviour

And now the LORD says, he who formed me from the womb to be his servant, to bring Jacob back to him; and that Israel might be gathered to him - for I am honored in the eyes of the LORD, and my God has become my strength - he says: "It is too light a thing that you should be my servant to raise up the tribes of Jacob and to bring back the preserved of Israel; I will make you as a light for the nations, that my salvation may reach to the end of the earth." (Isaiah 49:5-6 ESV)

Then he said to them, "These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled." Then he opened their minds to understand the Scriptures, and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. (Luke 24:44-47 ESV)

He answered, "I was sent only to the lost sheep of the house of Israel." (Matthew 15:24 ESV)

"Indeed, We sent forth among every nation a Messenger,; saying: 'Serve you God, and eschew idols.' Then some of them God guided, and some were justly disposed to error. So journey in the land, and behold how was the end of them that cried lies. (Quran 16:36 Arberry)"

Muslims claimed that Allah send prophets to every nation and Jesus is one of them, being sent to the Jews. But the people kept corrupting the message of the prophets and so Allah sent Muhammad to be the last and universal prophet for all people for all time.

Firstly, we have to take note that Jesus is not sent to Israel alone. But He had to be sent to Israel first, to fulfil the scripture.

Secondly, God's Word stand forever but Allah's word through his many named and unnamed prophets always got lost without a trace. For the Taurat (Torah), Zabur (Psalms) and Injil (Gospel), the Muslims claimed that they were corrupted by Jews and Christians. Given Allah's bad track record, how can I be sure that the Koran is not corrupted by the Muslims?

Forever, O LORD, your word is firmly fixed in the heavens. (Psalm 119:89 ESV)
The grass withers, the flower fades, but the word of our God will stand forever. (Isaiah 40:8 ESV)