Thing to Begin with

"You are just like a stone. No expression – just like stones. No difference at all"

The stone.
Which one was it being referred to? 

The one that can either push people towards the Heaven, or become one of the fuel in Hell. 
Or.. is it like the static one in the cave, that is going nowhere? 

Then 'When you're lost and alone, you'll be sinking like a stone' runs through my head. 

Urgh, I don't wanna lose. And I am not alone. (Never am I, right?)

Then I start walking again, with My Dear now, by my side.
And a smile on my face.

For it is the exact thing to begin with.