Working according to Ahad Hadith in matters of `Aqidah and Muslims' `Aqidah about `Isa

Q: I am a Muslim girl who believes that Allah saved `Isa (Jesus, peace be upon him) from crucifixion and raised him up to Him casting the likeness of Jesus on one of his disciples who was then crucified instead. I also believe that `Isa will return once again before the Day of Resurrection to kill the Antichrist. A few days ago, I read a book entitled, 'Comparative Religion and Orientalism', by Ahmad Shalaby, a professor of Islamic History, Cairo University. The book states that `Isa was not lifted up to the Heavens, instead, he disappeared from the sight of his enemies, died, and was buried like any ordinary person. The professor added, 'the Hadiths referring to the descent of `Isa (peace be upon him) to kill Al-Masih Ad-Dajjal at the end of time, are Ahad Hadiths (a Hadith which at some point in the chain has only a single narrator) which are not accepted in matters of `Aqidah.I was shocked when I read that this is the opinion of some of our great scholars such as, Shaykh Al-Maraghy, Shaykh Shaltut, Sayyid Qutb, and others. I am confused. What is the meaning of 'Hadith-ul-Ahad'? Are they not accepted - as stated by the professor - in matters of `Aqidah even if they were reported in the Two Sahih Books of Al-Bukhari and Muslim? What is the Islamic `Aqidah concerning the Messiah (peace be upon him)? I would like to thank you for your efforts in serving Da`wah (calling to Islam)

(Part No. 3; Page No. 332) A: First: Hadith is divided into Hadith Mutawatir and Hadith-ul-Ahad. Hadith Mutawatir is a Hadith reported by a significant number of narrators throughout the chain of narration whose agreement upon a lie is impossible. The narrators must base their narration on sense perception, i.e. something heard or seen. Hadith-ul-Ahad is that which lacks any of these conditions. Hadith Mutawatir acts as a proof in matters related to `Aqidah and subsidiary matters exactly like the Qur'an. According to the majority of scholars, Hadith-ul-Ahad acts as a proof in subsidiary matters. Likewise, according to the preponderant view among the scholars, it is reliable in matters related to `Aqidah. Moreover, whoever maintains that it is not reliable in doctrinal matters has fallen into a contradiction when citing this very category of Hadiths in support of their doctrinal and principal matters. They have even resorted to a weak narration to back their opinions. Second: According to the doctrine of the Salaf whom the Prophet (peace be upon him) described as the best generation, `Isa (peace be upon him) was not killed or crucified, nor did he die. On the contrary, Allah raised him body and soul into heaven. He will descend at the end of time, and will break the cross, kill the swine, and call people to believe in the Message of Muhammad (peace be upon him). They will all believe in him, even the Jews and the Christians as indicated in the Qur'an and the authentic Sunnah.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.