The Qur'an does not state that validity rests in more than one religious tradition, it says the religion with Allah is Islam. Now, I know you're a baatini and thus you interpret Islam in that statement as meaning "the primordial, formless truth" rather than the religion of Sayyidina Muhammad (salallahu alayhi wa sallam), but that is not how Muslims have traditionally interpreted that verse, or any other referring to the exclusiveness of Islam. I strongly suggest you read a book called Hujjatullah al-Balighah by Shah Wali Allah (rahimahullah). It includes a detailed and brilliant explanation of the relation of Islam to the other religions, and why it is that Islam abrogates all previous religions.