Why do the Orthodox venerate and incorporate icons into their worship? It comes down to the belief that we see the world, as Father Stephen says, as a one-storey universe. God is here and now. The Church here on earth is the same as in heaven. The incarnation is what brings this about.
Basically, icons give us a picture of the worship in heaven. As we worship here on earth the saints are worshiping in heaven. The icons help us in seeing that. They give an incarnational presence.
It has a lot to do with our view of the Church being the same on earth and in heaven. The communion of the Saints is key in this. We believe that since heaven is here and now that the saints are with God and worship Him. If heaven is here and now that means it is among us and we are all one Church. We are never alone for the saints are with us. We just aren’t able to see that; we aren’t able to perceive it with our limited vision. However, I think we can learn to see; we can enlarge our vision, our understanding.
When I enter into the nave of our parish and I see the icons making present the reality of worship I feel at home. It is an overwhelming feeling to be connected to the Church in heaven and on earth as we participate in the Divine Liturgy that has been prayed for 1,500 years in its current form by billions, if not trillions, of Christians. It is an overwhelming sense of belonging to know that that many people have said those same prayers and that millions more are saying them with us in the presence of the saints as we worship the Holy Trinity together.
The icons give us a picture of reality. We can widen our vision, our spiritual vision, if we begin to understand that there is no dividing line between heaven and earth; we can widen our vision by realizing that there is one Church in heaven and one Church on earth. The Church is fully one and united in Christ in heaven and earth. When venerate the icons because they are worthy of our reverence. They make present the lives of the Saints. We have respect and love for those who went before us. We honor them. We participate in worship of the All Holy Trinity with them. There is a richness to the Orthodox form of worship. It engages us fully, holistically. One Orthodox Christian said, “We see the Gospel in the icons.” Words fall short when spoken alone. The icons helps us to see the Gospel, to see reality in a way in which our eyes prohibit us.
This is not a full theology concerning the icons, but a basic induction to them as I have come to understand them. In summary, I once read that the “icons do with colors what the Scriptures do with words.” I wanted to write this up to give a basic, simple understanding of the icons. I’m sure others can answer the question of why we have them and venerate them better, but this is how I have come to understand them.