Spirituality is the process of learning who we are, even when we never reach, at least in this lifetime, total direct conscious contact with the Design Integrity Gestalt of the Ground of Ultimate Being (otherwise titled "God"). My conceptual label blends R. Buckminster Fuller's "design integrity of the Universe," and Paul Tillich's "Ground of Being," with "gestalt" to indicate the functional whole without properties derivable by summation of its parts.
That's alright; we are all embraced by that Mysterious Boundless Being--as it is also embodied within us--whether we realize it or not. At some point, though, it should be obvious that words do not get us there; there must be some direct experience (although each quotidian moment already IS direct experience). All religions, and even, I would say, some nonreligious systems of thought, attempt to engender some of that direct experience of the Ultimate Reality.
The spiritual principle, then, is to comprehend that we are centered (there is no other place) in that Transcendent Luminosity and simply live (even unconsciously) as embedded, nonseparated energies in the Design Integrity Gestalt of the Ground of Ultimate Being. The key is the comprehension, the realization, that we are always embraced by and embedded in the Great Gestalt.
The classical crossover piano music and the rain pattering my window and the clunking bamboo chimes are more than nice on this luminous day.