Imam Sadiq (peace be upon him): Mufaddal ibn Umar said: I asked my master Imam Sadiq (peace be upon him): "... What will Imam Mahdi (may Allah hasten his noble reappearance) be like at the time of his appearance?" He said: "O Mufaddal! He will appear amid a state of doubt, until his affair becomes clear, his name is raised high, his affair becomes manifest, and his name, kunya and lineage are proclaimed, and his fame spreads on the tongues of the followers of truth and falsehood, and of those who agree and those who oppose ..." I said: "My master! What is the interpretation of: 'so that He may make it prevail over all religions, even though the polytheists may dislike it' (al-Tawba/33)?" He (peace be upon him) said: "Its interpretation is this verse: 'And fight them until there is no fitna [polytheism and the denial of freedom], and religion [and worship] is wholly for Allah' (al-Anfal/39). O Mufaddal, by Allah! He will lift disagreement from among the nations and religions, and all religions will become one, as Allah has said: إِنَّ الدِّینَ عِنْدَ اللهِ الْإِسْلامُ [Indeed, the religion with Allah is Islam], and He has also said: 'Whoever accepts any religion other than Islam, it will never be accepted from him, and in the Hereafter he will be among the losers' (Aal Imran/85)." I said: "My master! Was the religion which his forefathers Ibrahim, Nuh, Musa and Isa (peace be upon them) and Muhammad (peace be upon him and his family) held the very religion of Islam?" He said: "Yes! It was this very religion of Islam and nothing else." I said: "Do you have proof from the Qur'an for this matter?" He said: "Yes! From the beginning to the end of the Qur'an is full of proof. Among them is the verse إِنَّ الدِّینَ عِنْدَ اللهِ الْإِسْلامُ [Indeed, the religion with Allah is Islam], and another is this verse: 'Follow the creed of your father Ibrahim; Allah named you Muslims in the earlier scriptures and in this heavenly Book' (al-Hajj/78)."