Spirituality is finding God in everything and everyone around you. To successfully find God in another, one must find God in oneself. To do this, one must know who one truly is. One wears various masks, for example; masks projected to one's employer will not be the same as a mask projected to one's subordinate. And that mask would differ from the mask projected to one's family members and friends. Consequently, one is wearing so many masks that one has lost their own sense of reality. One does not know who one truly is anymore.
To find one's true self, one must peel away these masks. That in essence is the concept of no self for the face behind the masks is the face that one will see in others around them. No self leads to a liberating sense of oneness and that is spirituality.