"What I see in Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of "humility." This is a genuinely religious feeling that has nothing to do with mysticism" (Einstein)

Hmm, on second thought, I beg to differ with the "genuinely religious" bit. Religions are social institutions, which may or may not have much to do with the "spiritual" at any given moment.   To say that humility is "...a genuinely spiritual feeling", or even "... a genuinely LOGICAL feeling" (!!) works much better in this context, imo.