Saying that a true Muslim is as well a true Christian and Jew
2-11-2010 | IslamWeb
Question:
I heard Imam Ahmed Qubasi in his program saying that a true muslim is as well true christian and jew. I told that to our local small masjid imam and he said said that is kufur and one should pronounce his islam again. He said no true muslim should say he's christian or jew even if he refer to the true scriptures.. I believe that Shiek Ahmed has wisdom that i need to know to defend him. Please explain, prefer if you provide evidence from Quran and Hadiths. Allah bless us all,
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
This statement that is attributed to the Shaykh whom you mentioned in the question is not clear, and one should not hasten to rule whether it is correct or wrong, let alone rendering its sayer a non-Muslim. Considering someone a non-Muslim is a very serious matter that may lead to error and misguidance. For more benefit on the conditions of considering someone a non-Muslim, please refer to Fataawa 91567 and 84943.
Since the Shaykh has a known program, then you may contact him or send him a question in order to know what he exactly meant by his statement.
Nonetheless, what we can say here is that Islam is the true religion by which Allaah abrogated all other religions. By the advent of Islam, Allaah does not accept any other religion; Allaah Says (what means): {Indeed, the religion in the sight of Allaah is Islam.}[Quran 3:19] Allaah also Says (what means): {And whoever desires other than Islam as religion-never will it be accepted from him, and he, in the Hereafter, will be among the losers.}[Quran 3:85] Allaah further Says (what means): {O People of the Scripture, there has come to you Our Messenger making clear to you much of what you used to conceal of the Scripture and overlooking much. There has come to you from Allaah a light and a clear Book [i.e. the Quran]. By which Allaah guides those who pursue His pleasure to the ways of peace and brings them out from darkness into the light, by His permission, and guides them to a straight path.}[Quran 5:15-16]
Moreover, Abu Hurayrah 
narrated that the Prophet said: “No Christian or Jew hears about me from this nation and dies while not believing in what I was sent with, except that he will be amongst the people of Hellfire.” [Muslim]
Finally, it should be mentioned that Islam as a creed is the religion of Moosa (Moses) and ‘Eesa (Jesus), may Allaah exalt their mention, and whoever followed these two Prophets at their time or after it but before what had been revealed to them was forged or before the religion of Islam - with which Muhammad came up - reached him, then he is a Muslim, and it might be that this is what the Shaykh meant.
Allaah Knows best.