How would you answer the claim that the belief of Mahdi and Dajjal came to Islam from other religions?
The fact that the belief of Mahdi and Dajjal (Anti-Christ) are present in almost all religions in some form does not necessarily show that it is wrong, nor does it show that it was influenced by them. On the contrary it may be evidence that it is an important question that interests the whole humanity. To confirm the true aspects and correct the wrong aspects of the heavenly religions is one of the reasons why Islam came, isnt it?
Mawdudi sees the view claiming that the belief of Mahdi is present in only the communities of other religions as a void belief and says the following:
I think our Prophet (PBUH) and the prophets before him may have said to their followers that before the end of the world Islam will emerge as the religion of the world, human beings will have to take shelter in the –ism of Allah after trying many –isms that are their own inventions or beliefs of human beings who suffers from grief and hopelessness and that it will be possible to be carried out by a leader who will act in accordance with the criteria presented by the Prophet (PBUH), and who will work hard to spread the Islam with its original identity. Which aspect of such good news is wrong?
When Mawdudi explains that the belief of Mahdi is present in non-Muslim communities, he says they took it from the accounts of other prophets but they interpreted by adding superstitions.(1)
Cant have Israiliyyat (Judaica:knowledge based ob Jewish sources) penetrated into Islamic sources?
It is possible. However, investigative Islamic scholars who acted very sensitively had worked hard to clean out the Israiliyyat that penetrated. While the hadith that Dajjal was tied in an island and the hadith of Ibn Sayyad were criticized in some ways, the narrations relating to Israiliyyat were cleaned out one by one. For instance, Ibn Hacar Asqalani points out that some hadith can be taken from the People of the Book (Jews and Christians). According to him the narration meaning Twelve thousand males and seven thousand females will escape from Dajjal and the narration Dajjal is not a man, he is a devil fastened with a chain of sixty rings can be taken from the People of the Book.(2)
(1) Abul-Ala al-Mawdudi, İslâmda İhyâ Hareketleri, trans. Halil Zefir. (Ankara: Hilal Yayınları: 1967)
(2) Ibn Hacar al-Asqalani, Fathu'l-Barî (Riyad: Muhibbuddin al-Hatip v.d. nşr.:1389), 16:205.