The Orthodox doctrine on the icon was formed since the very beginning of Chrisianity, together with their veneration, but it was only during the 8 th and 9 th centuries that it got its final form, i. e. at the time of the oikonomacheia (Patriarch German, Pope Gregory II, John of Damascus, St. Theodor Studition, etc.).
The basis for the complete Church oikonomia was provided by the Seventh Ecumenical Council, which adopted the dogma on the veneration of icons, which is founded upon the knowledge of the Incarnation, i. e. of the salvation in Christ, which is not only the proclamation of the word of God, but also of the Image of God, revealed through the God-Man Jesus Christ.
The icon is a picture, a portrait of the heavenly images and sacred events, but saying this we cannot exhaust its essence and significance. The theological- ecclesial essence of the icon is to be found in the specific relationship between the picture and the prototype on the icon, which is contained in the fact that the prototype participate on the picture. It is a sort of presence, presentation, manifestation of the prototype on the picture, it is a miraculous realism of the icon.
The possibility of the icon as a sacred picture is given in Christ’s Incarnation. Chist is the true icon. It is in Christ's Incarnation that some iconological errors of Nestorianism and Monophysitism have been overcome. In the same way as Christ appeared in the body, so also He, through the icon-painting appears on the icon. The picture is infinitely higher than a portait, but also much less than the unique Incarnation: matter on the icon remains dead, but one who is painted is alive, alive not only independently from the icon also on the picture, icon.
The total iconography (painting of the saints, angels, God Father, Son and Holy Spirit) is permeated by Christ. Christ, as the New Adam, reestablishes the lost icon of God (1 Mos. 5, 1) in the salvation, not only in Himself, but, through Himself, also in others, and especially, in a higher degree, in the saints. The saint is an icon where Christ is reflected. The link between the angels and Christ is not only according to the creatoi, but, first of all, according to the ministry (Hebr. 1, 14). The angelophania is in this sense Christophania. God Father is in the terms of the icon comprehensible as »the Father of our Lord Jesus Christ« (2 Cor. 1, 3). The conection of the Holy Spirit with the Son is permanent in the Incarnation (and mission) of the Tirnitarian God in Christ. There is an association of the events, so that the symbolism in the presentation-painting of the Holy Spirit is a reflection of that association (interrelation).
The veneration of icons is therefore in fact the veneration of God, for it has its limits and corrective in the fact that the prototype, which is in God, is the object of orship, whereas the very picture deserves veneration.