Today we celebrate the “triumph of orthodoxy”, meaning of the true faith. It celebrates the final victory over iconoclasm in 842, after 130 years of repeated struggles. The Synod of Constantinople had reaffirmed the Seventh Ecumenical Council’s teaching on the proper use of images in Christian worship, and to celebrate the event the population of Constantinople took part in a huge procession from the Blachernae Church to Hagia Sophia, carrying icons and other images which had been hidden away in homes and monasteries and now could be restored to the churches. Every parish holds a similar procession today, as the Council had decreed that the first Sunday of Lent, which was the date of that first procession, would include this remembrance. Today, the service reflects both the original feast, Sunday of the Prophets, and the triumph of orthodox belief over all heresies.
"We define that the holy icons, whether in color, mosaic, or some other material, should be exhibited in the holy churches of God, on the sacred vessels and liturgical vestments, on the walls, furnishings, and in houses and along the roads, namely the icons of our Lord God and Savior Jesus Christ, that of our Lady the Theotokos, those of the venerable angels and those of all saintly people. Whenever these representations are contemplated, they will cause those who look at them to commemorate and love their prototype. We define also that they should be kissed and that they are an object of veneration and honor (timitiki proskynisis), but not of real worship (latreia), which is reserved for Him Who is the subject of our faith and is proper for the divine nature. The veneration accorded to an icon is in effect transmitted to the prototype; he who venerates the icon, venerated in it the reality for which it stands".