Sacred.

Nearest I can figure, this is how this whole "sacred", idea works.

A person arbitrarily picks an object, or idea, or set of ideas, decides it's not only very special to them, but that it should be very special to you, and if it isn't, they get to have hurt feelings.

And if society backs up their special feelings, they get to sue you, hurt you, or kill you over it.

Neat trick.

(Also see "faith", "holy", and "blasphemy")