I do not feel there would be much contention discussing the Catholic origins of Protestantism.
There are any number of false religions that though they may teach some truth are not the Church.
So, maybe more precise, what about the Catholic origins of Islam -or is Islam some sacred cow? Or as some 'progressive' intellectual elites claim -are all religions equal?
Or even as President Obama claims -to paraphrase: Islam has given us much good...The Christian Origins of Islam
Near the bottom of the pit of hell, Dante encounters a man walking with his torso split from chin to groin, his guts and other organs spilling out. “See how I tear myself!” the man shrieks. “See how Mahomet is deformed and torn!” For us, the scene is not only gruesome but surprising, for Dante is not in a circle of false religion but in a circle reserved for those who tear the body of Christ. Like many medieval Christians, Dante views Islam less as a rival religion than as a schismatic form of Christianity.
Peter J. LeithartA handful of Western scholars now think there is considerable historical truth to Dantes view. According to the standard Muslim account, the Quran contains revelations that Allah delivered to Mohammed through the angel Jibril between 609 and 632. They were fixed in written form under the third Caliph in the mid seventh century. Islamic scholar Christoph Luxenberg doubts most of this. In 2000, he published the German edition of The Syro-Aramaic Reading of the Koran, whose restrained title and dispassionate tone belie its explosive arguments-explosive enough for the author to hide behind a pseudonym. The book has been banned in several Islamic countries.
One of Luxenbergs central arguments is that the Quran is an Arabic translation of an original Syriac/Aramaic text. Luxenberg is able to resolve oddities in the Arabic text by treating them as erroneous Arabic translations of an original Syriac text. Words that have no Arabic source turn out to be garbled versions of common Syriac terms. Luxenberg even finds evidence in the Quran itself for treating it as a translation. By his rendering, Sura 44:58 says “we have translated [the Koran] into your language so that they may allow themselves to be reminded.”