Assuming at least some things are sacred, what makes them sacred? What makes something profane? If it is as simple as "god makes things sacred" then why is the notion of the sacred present in animism (which lacks a notion of god)?
A closely related question: What does it mean to say that something is sacred?
I believe that sacredness means a space, an item or more abstract things which are of important significance on cultural or historical levels.
even if I am not a Bible believer, I believe the Bible to be sacred because of its timeless content, and the profound historical and cultural role it has played throughout the centuries, it is both a subconscious and a conscious sense of respect. the content of things, the effort put into them, and their importance to the cultures of the world are some of the elements which make something sacred.
to give an analogy, think of young Indiana Jones, as a young man he fought to restore a single gold cross from the 15th or 16th century and get it into a museum because of his sense for the preservation of history, while the bandits he confronted wanted to sell it for money. this is what I'm getting at here.
think about this: sometimes we hear people say 'nothing is sacred any more', what they mean to say is that many people do not show respect any more, people will smear anything and would not show a sense of appreciation for context or space.