I’ve taken a deep interest recently in Frithjof Schuon. This man has been involed in advaita vedanta, hinduism, sufism (The same lineage I belong to), christian mysticism and native american spirituality and as one dear friend in this forum once said… Nectar from different flowers makes the honey comb much sweeter 
http://www.youtube.com/results?search_query=frithjof+schuon&oq=frithjof&gs_l=youtube.3.0.0l5.294.556.0.1625.2.1.0.1.1.0.215.215.2-1.1.0...0.0...1ac.1.HVNFOBzoWWg
http://en.wikipedia.org/wiki/Frithjof_Schuon
There’s a movie about his bio as well:
http://www.amazon.com/Frithjof-Schuon-Messenger-Perennial-Philosophy/dp/1936597047/ref=sr_1_7?ie=UTF8&qid=1355509219&sr=8-7&keywords=frithjof+schuon
Have I ever said that the path to God passes through Mecca? If there
were any essential difference between a path that passes through
Benares and one that passes through Mecca, how could you think that
I would wish to come to God “through Mecca,” and thereby betray
Christ and the Vedanta? In what way does the highest spiritual path
pass through Mecca or Benares or Lhasa or Jerusalem or Rome? Is the
Nirvana of Mecca different from the Nirvana of Benares simply
because it is called fanâ and not nirvâna? Do I have to explain to you
once again that either we are esoterists and metaphysicians who transcend
forms—just as Christ walked over the waters—and who make no
distinction between Allah and Brahma, or else we are exoterists, “theologians”—
or at best mystics—who consequently live in forms like fish
in water, and who make a distinction between Mecca and Benares?
(letter to Albert Oesch, May 15, 1932)
Thank you for sharing this, very interesting.
Salam
In esoterism there are two principles which may be actualized sporadically
and at different levels, but always in a partial and contained
manner: the first is that fundamentally, there is only one
religion with various forms, for humanity is one and the spirit is one;
the second principle is that man bears everything within himself,
potentially at least, by reason of the immanence of the one Truth.
—Frithjof Schuon, In the Face of the Absolute