We know what happened in history to Jesus.

The Quran claims about the cross:

¹⁵⁷And 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)]: ¹⁵⁸But 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.

An-Nisa 4:157-158, Muhsin Khan

The death of Jesus on the cross is historically factual and agreed upon by Christians. It was taught by Jesus and the earliest followers of Jesus. 

Jesus taught about the cross:

Now as Jesus was going up to Jerusalem, he took the twelve disciples aside and said to them, “We are going up to Jerusalem, and the Son of Man will be betrayed to the chief priests and the teachers of the law. They will condemn him to death and will turn him over to the Gentiles to be mocked and flogged and crucified. On the third day he will be raised to life!”

Matthew 20:17-19

Jesus’ disciples taught that Jesus died on the cross and rose again from the dead.

Jesus chose disciples (Apostles) to witness and testify to what He did and taught. One of Jesus’ foremost disciples was Peter. Jesus appeared to Peter after He died and rose again. Peter testifies to Jesus’ death and resurrection,

Praise be to the God and Father of our Lord Jesus Christ! In his great mercy he has given us new birth into a living hope through the resurrection of Jesus Christ from the dead.

1 Peter 1:3

Another disciple Jesus chose to witness and testify to what Jesus did and taught was John. John testified to Jesus’ death and resurrection,

This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers.

1 John 3:16

Islam is unlike Judaism and Christianity because it denies history. It does not build on God’s previous revelation. God makes Himself known in His Word and His work in history.  

George Eldon Ladd also pointed out the importance of history as it relates to the beliefs of the Hebrew-Christian faith:

The uniqueness and scandal of the Christian religion rests in the mediation of revelation through historical events. The Hebrew-Christian faith stands apart from the religions of its environment because it is an historical faith, whereas they were religions rooted in mythology or the cycle of nature. The God of Israel was the God of history, or the geschichtsgott, as German theologians so vividly put it. The Hebrew-Christian faith did not grow out of lofty philosophical speculation or profound mystical experiences. It arose out of the historical experiences of Israel, old and new, in which God made Himself known. This fact imparts to the Christian faith a specific content and objectivity which set it apart from others…. The Bible is not primarily a collection of the religious ideas of a series of great thinkers. It is not first of all a system of theological concepts, much less of philosophical speculations….The recital of God’s historical acts is the substance of Christian proclamation.¹“The Knowledge of God: The Saving Acts of God” in ed., Carl F. H. Henry, Basic Christian Doctrines [New York: Holt, Rinehart and Winston, 1962], 7-13.
Another word for the Christian proclamation is “gospel.” Gospel means “good news” about something that has happened in history. The Qur’an uses the word “gospel” (Injeel), but redefines what it meant centuries earlier. The Quranic Injeel was a book given to Jesus from heaven (cf. Qur’an 5:46-47; 57:27). Jesus was never given a book from heaven. See David Thomas, “Muslim Conception of Gospel”, in: Encyclopaedia of Islam, THREE, Edited by: Kate Fleet, Gudrun Krämer, Denis Matringe, John Nawas, Everett Rowson. 

What happened in history is important, because you, I, and loved ones will die.

Here are the historical facts:

• The Apostle Peter saw the resurrected Jesus (Acts 2:32-36).
• Muhammad lived more than 500 years after Peter’s eyewitness testimony to Jesus’ resurrection from the dead.
• Muhammad contradicted the Apostle Peter’s witness to what God had done in Jesus Christ.²The Quran refers to Jesus as the Messiah/Christ (Quran 3:45). However, the title Messiah/Christ refers to Jesus’ death on the cross, resurrection, and ascension to the right hand of God. Jesus’ apostle Peter, an eyewitness to the resurrection of Jesus and His ascension into heaven proclaimed this in Acts 2:32-36 and wrote about it in 1 Peter. 
• Muhammad is dead and buried.
• You will die.
• Believe in Jesus, and be baptized for the forgiveness of your sins, and you can have certainty that you will inherit eternal life. 

Jesus said,

I told you that you would die in your sins; if you do not believe that I am the one I claim to be, you will indeed die in your sins.”

John 8:24

You may also be interested to read:

Muhammad’s fifth marriage to Zaynab was not lawful.