These murals are what are considered Early Christian art, though in actuality it is far more than just art. Christian art was intended to illustrate the power and glory of Christ; beauty or aesthetic principles were of no concern. The images are symbols, almost like a form of code, since the Christians were in hiding from the Romans. In fact, the official strategy was to use Roman symbols to tell Christian stories. So we see images of animals, birds, and plants—for example, a goldfinch. Goldfinches appeared in Roman art as merely a bird; however, it was a known fact that goldfinches ate thistles and thorns, and so to the Christians, the bird was a reminder of Jesus' crown of thorns. Other such symbols were dogs (to represent loyalty) and ivy (to represent eternal life). Here is a mural from a catacomb: an image of a shepherd feeding his sheep. To Roman guards, the image is harmless, but Christians remembered Jesus' words that He is the good shepherd, and that He lays His life down for His sheep (John 10:11).