Today the Church celebrates the feast of one of my favorite saints-St. John of Damascus. (c. 676-754/787 A.D.)
St. John lived between the 7th and 8th centuries and fought against the heresy of Iconoclasm. "Iconoclasts" viewed religious images of any kind as idolatrous. Against them were the orthodox "Iconodules" who regarded images as helpful in the aid of worship.
St. John brilliantly defended the veneration of images. He clarified the distinction between worshipping God and venerating His image. One prays to God himself, not a piece of wood or a mosaic. The picture is there to help focus one's prayer--very much like the Gospel accounts do. St. John's argument consisted in comparing images to the Gospel. His brilliant insight is simply this: the Gospels are verbal accounts of the Lord's words and actions, while icons are pictorial accounts. If you reject the latter, you are in danger of rejecting the former, because the content is the same.
There a lot of history behind this particular controversy. It is interesting to note that Islam may have influenced the iconoclast heretics since Mohammud taught that images were sacreligious and banned the production of them.
The 2nd Council of Nicea (787 A.D.) which was the 7th Ecumenical Council declared that the use of images in sacred art is not idolatrous. Images are used to help contemplate the divine mystery.
St. John is considered the last of the Church Fathers.
St. John of Damascus, pray for us.