Prelude to the Triumph of Orthodoxy

"Given this state of affairs and stepping out as though on the royal highway, following as we are the God-spoken teaching of our holy fathers and the tradition of the Catholic Church--for we recognise that this tradition comes from the Holy Spirit who dwells in her--we decree with full precision and care that, like the figure of the honoured and life-giving Cross, the revered and holy icons, whether painted or made of mosaic or of other suitable material, are to be exposed in the holy churches of God, on sacred instruments and vestments, on walls and panels, in houses and by public ways; these are the icons of our Lord, God, and Saviour, Jesus Christ, and of our Lady without blemish, the holy Theotokos, and of the revered angels and of any of the saintly holy men.  The more frequently they are seen in representational art, the more they are those who seem them drawn to remember and long for those who serve as models, and to pay these images the tribute of salutation and respectful veneration.  Certainly this is not the full adoration in accordance with our faith, which is properly paid only to the Divine Nature, but it resembles that given to the figure of the honoured and life-giving Cross, and also to the holy books of the gospels and to other sacred cult objects.  Further, people who are drawn to honour these icons with the offering of incense and lights, as was piously established by ancient custom.  Indeed, the honour paid to an image traverses it, reaching to the model; and he who venerates the icon, venerates the person represented in that image.

    "So it is that the teaching of our Holy Fathers is strengthened, namely, the Tradition of the Catholic Church which has received the Gospel from one end of the earth to the other.  So it is that we really follow Paul, who spoke in Christ, and the entire divine apostolic group and the holiness of the Fathers, clinging fast to the Traditions which we have received [2 Thess 2:15].  So it is that we sing out with the prophets the hymns of victory to the Church:  Rejoice exceedingly, O daughter Zion, proclaim O daughter of Jerusalem; enjoy your happiness and gladness with a full heart.  The Lord has removed away from you the injustices of your enemies, you have been redeemed from the hand of your foes.  The Lord the King is in your midst, you will never more see evil [Zeph 3:14f], and peace will be upon you for time eternal."

Second Ecumenical Council of Nicaea, 787