As an atheist, I am frequently asked what keeps me from committing immoral acts, what prevents my corruption, what, essentially, protects the spirit it is assumed that I do not believe I have. This thread, essentially, is an answer to that.
Spirituality, to me, is defined as the sum synergetic total of my intellect, my reason, and my honor. The importance of spirituality to me is that, without spirituality, I am less than what I can be. Without spirituality, I am a simple common animal, on the same level as any other whom is still ruled by the law of the jungle. I do not consider humans, in general, to be animals. The distinction is spirituality, versus instinct. Instinct is the default programming. Instinct is what you follow when all else has abandoned you. Yes, it is true that some humans resort to this on a more than frequent basis, and some animals have shown an ability to surpass it as well, but, in general, the common animal is ruled by instinct, while the human has the ability to surpass instinct, through the use of spirituality.
Intellect is the ability I have to put various facts to work for me. Intellect is the physical, the material, the objective side of things. Intellect is what allows me to make the connection between chemical properties of elements, to electrical properties of batteries, to the use of a flashlight. It is more than the basic gathering of useful things for survival; it is the gathering, storing, and analyzing of data for current and future use, not just for survival, but for comfort and even entertainment.
Reason is the ability to work out the responses of hypothetical situations. In particular, moral actions are largely determined by reason. I do not murder, not because I am forbidden by the God of the Babylonians to do so, but because I recognize it to be an action which would have disastrous effects on my personal psyche, to say nothing of the actions society will take on me after having done so. I exist because I enjoy existing, I enjoy the sunlight, I enjoy the challenge of discovery, not because I am testing myself for an existance yet to come in another realm.
Honor is the combined result of my courage, my obligations, and my sense of justice. This serves as my shield against corruption. Actions are measured against these things, and their effects are weighed and found to be honorable or dishonorable. Stealing a candy bar, for instance, requires a mild amount of courage, no obligation, and a definite lack of justice. Very little honor there. Stealing a loaf of bread to feed a hungry child requires a bit more courage (as your actions are endangering not just yourself, but the child) and are high in obligation (in regards to your duty to the child). They, however, violate the law, and the law is part of justice (not all of it, just part of it). While this is a dishonorable act, it isn't as bad as stealing for selfish pleasure. Getting a job mucking out fish stalls requires a certain courage (more humility, really), is definitly fulfilling your obligation, and is well-withing the bounds of justice. This would be considered and honorable act.
These three immaterial, boundryless aspects of myself are what define my spirituality. They are part of what makes me who I am. They are not defined by an external code or authority, but rather by my own abilities and beliefs. This is my spirit, or soul, if you wish. This is the most precious part of myself.
Call me an over achiever!