"Jesus used this incident and this work of art [the brass serpent] as an illustration of his coming crucifixion: "And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up ..." (Jn. 3:14-15). What was Jesus using as his illustration? A work of art.

But then perhaps someone will say, "Yes, but they smashed it. Hezekiah broke it up in 2 Kings 18:4." That's true. ... But why did Hezekiah smash the brazen serpent? "And he [Hezekiah] brake in pieces the brazen serpent that Moses had made; for unto those days the children of Israel did burn incense to it." Did he smash it because it was a work of art? Of course not, because God had commanded Moses to make it. He smashed the  work of art because men had made it an idol. What is wrong with representational art is not its existence but its wrong uses."

--Francis Schaeffer, Art and the Bible