When we consider the world outside ourselves, it is made up of two realities. The first is the ultimate reality of God, the one who made us, and to whom we are everlastingly in debt. The other reality is creation, which includes all the created order that is external to myself. When I am out of fellowship with God, the only thing available to pursue besides Him is some created bauble. And when I pursue that created thing, trying to get from a finite thing what only the infinite can provide, I have fallen into the vanity of idolatry.
