In non-supernaturalist terms, ‘Spirituality’ is merely another name for human nature. Or, in other words, Spirituality refers to the Human Spirit. The higher or positive aspects of human nature are, for many people, symbolized by metaphorical personifications known as gods. ('God' in the monotheistic Abrahamic religions). Another way of putting it is that the gods are fictional representations of these aspects.
What is it? I will list, in non-supernaturalist terms, some of the wide-ranging variety of answers humankind has given to that question:
1. Our highest values – Goodness (the moral and ethical realms). Truth (the objective and scientific realms). Beauty (the subjective and aesthetic realms).
2. Our loftiest ideals – e.g. Love, compassion, mercy, perfection, justice, freedom, creativity, certainty, power, etc.
3. Our peak experiences – e.g. Wonder, awe, mystery, gratitude, uniqueness, oneness, interconnectedness, security, risk-taking, etc.
4. Our areas of ultimate concern – e.g. Self, family, community, nation, humanity, nature, planet, universe, etc.
What could constitute a non-supernaturalist religion? Here are some of the usual requirements:
First, the veneration, reverence, honouring and upholding of the positive aspects of our spirituality. Second is the apprehension and realization of these aspects; in simpler words, getting to know and understand them. Third is the manifestation and actualization of these aspects; in simpler words, bringing them into being in our world, both in ourselves as well as in others.
We must, however, take into account all our values, all our ideals, all our experiences and all our concerns. Even low values, mundane ideals, devastating experiences, base concerns, as well as vile impulses and crass desires, etc. Within the Abrahamic religions, most of the latter are labelled as ‘Demonic’. These religions use the Demonic as a metaphorical personification of humanity’s lower or negative aspects.
In non-supernaturalist terms, 'Spirituality' is merely another name for human nature.
David Miller, Philosophy Forum, Sunday 5th May 2013.