Why did Jesus (peace be upon him) not die, and why will he appear at the End of Time as one of the signs of the Hour?

Firstly: The descent of Jesus (peace be upon him) at the end of time, his killing of the Antichrist (Dajjal), his breaking of the cross, his killing of the swine, and his call for the People of the Book to embrace Islam or face the sword, is established by the Qur'an and Sunnah. Allah (the Most High) says: (And indeed, He [Jesus] will be [a sign for] knowledge of the Hour) (Az-Zukhruf/61). Ibn Kathir interpreted this as proof of Jesus' descent before the Day of Judgment. The hadiths have been transmitted widely and successively (mutawatir) regarding the descent of Jesus as a just ruler.

Secondly: Among the wisdoms of Jesus' (peace be upon him) descent is the manifestation of Islam and the completion of its comprehensiveness. He will descend to clarify the truth of his affair to people and to settle what they differed upon. He will support the Muslims and fight the Jews, kill the Dajjal, and oblige the Christians to embrace Islam without accepting the jizya (tribute). The Messenger of Allah (peace be upon him) said: "By Him in Whose Hand is my soul, the son of Mary will soon descend among you as a just judge. He will break the cross, kill the swine, and abolish the jizya." (Narrated by Al-Bukhari and Muslim). This confirms the invalidation of other religions and the establishment of proof against the People of the Book. Among the wisdoms is also a refutation of the Jews' claim that they killed him, and to show their falsehood by demonstrating that it is he who will kill them, or due to the nearing of his death so that he may be buried in the earth.