I've never been really happy with any of the definitions of religion. About the closest I've come is my quip of "It is really difficult to discuss religion but I can gab about spirituality with anyone." The other day, I came up with what seems to be to be essence of religion and that is: to celebrate and/or venerate. It also involves spirituality in some way but not always directly. I think my biggest problem with finding a definition that I was happy with is that I was hung up on the forms and rituals of religion when those are demonstrations of religion rather than what religion is.