the Word came into the world
The sage sought Him out in every place.
They saw him not, but sensed His presence everywhere.
They found Him in living beings, in the mountain crags and flowing streams, in seas and winds.
He was not these things,
But He spoke in these things, guiding them.
All things followed His Course.
Therefore the sages called Him also by His other name:
The Way (Tao),
The Course that all things are to follow.
(Hieromonk Damascene, Christ the Eternal Tao, Valaam Books, 1999, Ch.10)
How is Christ the image of the invisible God?
First of all, Christ is the image of the Father by nature, He is God from God, light from light, the Son of God co-eternal with the Father. As such He is invisible.
the Son of God took on a human nature, He became
"the image of the invisible God" for mankind. Christ is the "Son of God" and the "Son of man" and as such we glimpse at God's nature and purpose through his presence, words and actions. By his words he revealed the Father who lets the sun shine and the rain fall on the good as well as the bad. By his actions, especially his death on the cross, He revealed the Father's saving will for all mankind. He said to Philip, "When you see me you see the Father". Christ does what He sees the Father doing because He is One with the Father. Through his humanity Christ shines with the love, compassion and the mercy of God who created man originally through, with and in his Son.
Scripture does not paint for us the physical likeness of Christ, but His God-like personality. When Christ ascended to his Father, mankind could no longer see his human face but still longs to see it because God gave us eyes to see with. So, in the Eastern Church images called Icons were painted to represent Christ. Their way of painting was symbolic rather than realistic. His facing forward brings his figure in direct relationship with the viewer as if to say, "Who do you say that I am?". As you can see he is painted with large eyes, long nose and small mouth indicating that He is now transfigured. The two lines on the forehead may signify the two natures in Christ, divine and human. The red undergarment symbolizes divinity while the blue outer garment is the color of the sky or human life. This means that God became human. The background gold represents the radiance of heaven while the cross points to His Sacrifice for the forgiveness of sins which paved the way to heaven for mankind. The Greek letters IC and XC are abbreviations meaning Jesus Christ.
The Eastern Church influenced by the Old Testament and Moslems beliefs began to question the use images as idolatry. In 726 AD Emperor Leo III began the attack on the use of Icons and many were destroyed. St. John of Damascus came to their defense with the following words:
These images are venerated, shown reverence and used in prayer and worship because they do not merely recall the reality which is in heaven but in a mysterious way make that reality present to the believer. Through faith the believer is in touch with the reality.