The Swiss-German philosopher Frithjof Schuon, also known as Shaykh `Isa Nur al-Din Ahmad to his followers, is perhaps the foremost representative of the mystical perennialist school*. He is the founder of "The path of Mary" (Tariqah Maryamiyyah) and among his well-known disciples are people like Seyyed Hossein Nasr, Martin Lings and Rama Coomaraswamy.
The following should be enough proof of his deviance from the religion of our Prophet . This is Frithjof Schuon speaking on the topic of "sacred nudity":
Know that Frithjof Schuon was a man who practiced what he preached. He claimed to have had several visions of the mother of sayydina 'Isa , the Virgin Mary, and he describes one of these visions in his Memoirs as follows:Sacred nudity -- which plays an important role not only with the Hindus but also with the Red Indians -- is based on the analogical correspondence between the "outmost" and the "inmost": the body is then seen as the "heart exteriorized," and the heart for its part "absorbs" as it were the bodily projection; "extremes meet." It is said, in India, that nudity favors the irradiation of spiritual influences; and also that feminine nudity in particular manifests Lakshmi and consequently has a beneficial effect on the surroundings. In an altogether general way, nudity expresses -- and virtually actualizes -- a return to the essence, the origin, the archetype, thus to the celestial state: "And it is for this that, naked, I dance," as Lalla Yogishvari, the great Kashmiri saint, said after having found the Divine Self in her heart. To be sure, in nudity there is a de facto ambiguity because of the passional nature of man; but there is not only the passional nature, there is also the gift of contemplativity which can neutralize it, as is precisely the case with "sacred nudity"; similarly, there is not only the seduction of appearances, there is also the metaphysical transparency of phenomena which permits one to perceive the archetypal essence through the sensory experience. St. Nonnos, when he beheld St. Pelagia entering the baptismal pool naked, praised God for having put into human beauty not only an occasion of fall, but also an occasion of rising towards God.
This degenerate cultist was also quite fond of painting nude women and even made a nude painting of the Umm al-Masih (this is a well-known fact and can easily be documented, but I know you understand my hesitation in posting the relevant links)."On my way to Morocco in 1965, when I was suffering from asthma and feeling ill to the point of death - owing to causes of a moral order - there occurred on the ship...a blessed contact with the Heavenly Virgin. And this had as its immediate result the almost irresistible urge to be naked like her little child; from this event onwards I went naked as mush as possible, indeed, most of he time...it was as if the contact with the Virgin had sanctified my body...A few years later - in the summer of 1973 - this mystery came upon me once again, and it did so in connection with the irresistible awareness that I am not a man like other men...
May Allah give Schuon and his admirers their just deserts.
* Followers of Perennialism or "Integral traditionalism" claim that that a variety of religions present today, like Judaism, Christianity, Islam, Buddhism and even Hinduism, share the same Divine origin and are based on the same metaphysical principles, sometimes called philosophia perennis.