Saint John of Damascus defended the use of imagery in the Church in three treatises published in the eighth century. Note that by Saint John’s time the use of imagery was already widespread and considered ancient, but there was a push by the “iconoclasts” in the East saying that all such imagery should be destroyed or removed by the Church. Saint John argued that in incarnating in the person of Jesus Christ, the invisible God made his own visible image, where prior God had given none. Saint John also argued that the prohibition on images was due to the immaturity and hardness of hearts of the Israelites, and that as we have matured into the adultness of faith we can reasonably use images in the appropriate context without being led astray. Saint John also pointed out that God himself had advised that the Israelites should use and venerate certain images, from the Bronze Serpent held up by Moses, to the Ark of the Covenant and the Cherubim, to the depiction of the heavens on the veil to the entrance of the Holy of Holies. He is also clear that Christians do not believe the images to be gods or to have any power in their own right, but that they are used to respect and venerate God’s own works (the Incarnation, the saints, etc…), and that by venerating the images we are not venerating the statue in its own right, but simply acknowledging our veneration of the saint itself, and that images help us to connect to the Bible stories and the saints.
Of course, Saint John of Damascus said much more than I have here, and provided long lists of quotes from even more ancient authors than himself attesting to the use of images as being an ancient Christian practice and not a later innovation.
