speaking personally, of course, I think I prefer to link spirituality not to faith, or to sacrifice, but rather inability of mankind to perceive the whole of reality.
Spirituality is just an acceptance of the fact that there are sights, sounds and experiences which fail to register in the spectrum of human perceptions. There are parts of reality that we fail to perceive, but they are part of reality regardless and effect the whole, even the parts we live in.

Spirtuality is simply opening towards the unknown that hides just beyond the veil of our senses, rather than hiding from it.