For me, it would mostly be the feeling I get from giving and receiving love. For me, I used to have bible class. I hated going to Sunday School and thought it was a waste of time, but everyone knows that 8th grade was the open you eyes call. I realized there’s so much more to life, the world was pretty small for me before I created a bond with God. And no you don’t have to believe in him to realize what makes love Special. Everyone has a different definition for it anyways.