This actually isn’t a novel argument; it’s simply one that you don’t hear very often through the filter of the MSM. But Islam argues that all the prophets who proceeded Muhammad, and the list of those prophets includes Moses and Jesus, were, in fact, Muslims whose message was garbled, either inadvertently or purposefully. In other words, Judaism is actually a misinterpretation of Moses’s Islamic message. Likewise, Christianity is a misinterpretation of Jesus’s Islamic message. (For example, Jesus didn’t actually foretell the appearance of the Holy Ghost (Spirit); Jesus was, in fact, foretelling the arrival of the Prophet Muhammad!
There is only one heavenly religion. All the prophets, from Adam to Muhammad, came to call [people] to that one religion. What is the name of this one religion? In the Koran it is named “Islam.” Thus, as the religion, Islam is not only the message that came to Muhammad, but rather the message that came to Muhammad, along with the message that came to Isa [Jesus], along with the message that came to Moses, along with the messages that came to all previous prophets.
However, in the language of the Koran, in science, in reality, there is no such thing as “the religion of Islam,” “the religion of Christianity,” and “the religion of Judaism.” No, there is only one religion; Islam is its final form. Christianity was a manifestation of it, and Judaism was a manifestation of it—but all of these are now called Islam.