EVERY one must recognise that a man who attempts to dishonour an image which has been set up for the glory and remembrance of Christ, of His holy Mother, or one of his saints, is an enemy of Christ, of His holy Mother, and the saints. It is also set up to shame the devil and his crew, out of love and zeal for God. The man who refuses to give this image due, though not divine, honour, is an upholder of the devil and his demon host, showing by his act grief that God and the saints are honoured and glorified, and the devil put to shame. The image is a canticle and manifestation and monument to the memory of those who have fought bravely and won the victory to the shame and confusion of the vanquished. I have often seen lovers gazing at the loved one's garment, and embracing it with eyes and mouth as if it was himself. We must give his due to every man, St Paul says "Honour to whom honour: to the king as excelling: or to governors as sent by him," (Rom. 13.7) to each according to the measure of his dignity.
St. John Damascene, Apologia against those who decry holy images.