Obviously, we need to start with definitions. But since I have not yet thought up my own or read a good, Biblically grounded definition of art, I'll start with what art is not.
"Art is the process by which all our emotions and feelings come bursting forth from ourselves as creative expression." I hear this a lot, in one form or another. It has also always seemed like a rather curious definition to me, as on the list of "Things That Come Bursting Forth From Ourselves" includes things like vomit.