Some extracts of Rihani's work:

From The Book of Khalid (1911): Book Khaled or Khalid Arabic Article (extracts)

Why this inflated conception of thy Me, when an infusion of poppy seeds might lull it to sleep, even to stupefaction? What avails thy logic when a little of the Mandragora can melt the material universe into golden, unfolding infinities of dreams? Why take thyself so seriously when a leaf of henbane, taken by mistake in thy salad, can destroy thee? But the soul is the source of both health and disease. And life, therefore, is either a healthy or a diseased state of the soul
... To graft the strenuosity of Europe and America upon the ease of the Orient, the materialism of the West upon the spirituality of the East, -- this to us seems to be the principal aim of Khalid.

... The spiritual and natural are so united, so inextricably entwined around each other, that I can not conceive of them separately, independently. And both in the abstract sense are meaningless and ineffectual without Consciousness. They are blind, dumb forces, beautiful, barbaric pageants, careering without aim or design through the immensities of No-where and No-time, if they are not impregnated and nourished with Thought, that is to say, with Consciousness, vitalized and purified. You may impregnate them with philosophy, nourish them with art; they both arise from them, and remain as skidding clouds, as shining mirages, as wandering dust, until they find their exponent in Man.

From A Chant of Mystics (1921):

We are filled with the water that heals, and through sealed, we are free;
We are not from the East or the West, no boundaries exist in our breast, we are free;
We are not made of dust or of dew, we are not of the earth or the blue, we are free.
Whirl, whirl, whirl, till the world, is the size of a pearl
Dance, dance, dance, till the world's like the point of a lance
Soar, soar, soar, till the world is no more.
 
From The Path of Vision (1921):

This is the highest, noblest form of spirituality -- the divine essence, which can be attained only by those who follow devotedly the path of vision, those who seek the light that bridges between eye and soul, and without which there can be no vision.
....And then it will dawn upon him that to give without expecting a return of any kind, immediate or distant, is as natural as to accept the gifts of the sun and the air and the mountain streams.

Indeed, we can be religious without being conscious of it; we can be religious without religiosity. To invest our heart-capital in the inherent goodness of humanity, to save a drowning swimmer, as Thoreau says, and go our way; this is the practical workaday spirituality which either points to us the path of vision or unfolds before us, according to our degree of enlightenment, one or more of its hidden secrets, which is a reward greater and more enduring than anything the world can give.

It is the harmony we achieve within us; the satisfaction we feel in a healthy, strength-giving reaction; the knowledge and power that every noble, unselfish deed affords; the only reward after all, in our triumphs and our consolation in defeat. Nay, there is no such thing as defeat for those who achieve harmony within. There is no such thing as a disappointment for those who continue to cherish the selflessness of which is born the noblest inner self. There is no such thing as failure for those who invest in the potentialities of the Ideal of the Soul.

And no matter how humble and obscure, how poor or how rich in the material things of the earth, the spiritually-bound and spiritually-directed of men, though they may not be counted among the great of history, are the only true heroes of the race, the agents 
of World-Spirit.