What makes art Christian art? Is it simply Christian artists painting biblical subjects like Jeremiah? Or, by attaching a halo, does that suddenly make something Christian art? Must the artist’s subject be religious to be Christian? I don’t think so. There is a certain sense in which art is its own justification. If art is good art, if it is true art, if it is beautiful art, then it is bearing witness to the Author of the good, the true, and the beautiful
R.C. Sproul, Lifeviews: Make a Christian Impact on Culture and Society