Jesus Christ is “the image of the invisible God.” — Col. 1:15
St. John Damascene, b. 675, Damascus; d. December 4, 749, near Jerusalem.
He writes to Christians against the iconoclasts,
“The Scripture says, ‘You have not seen the likeness of Him [the Holy Trinity: one God three Persons].’ How then depict the invisible? How picture the inconceivable? How give expression to the limitless, the immeasurable, the invisible? How give a form to immensity? How paint immortality? How localise mystery? It is clear that when you contemplate God, who is a pure spirit, becoming man for your sake, you will be able to clothe Him with the human form.
When the Invisible One becomes visible to flesh, you may then draw a likeness of His form. When He who is a pure spirit, without form or limit, immeasurable in the boundlessness of His own nature, existing as God, takes upon Himself the form of a servant in substance and in stature, and a body of flesh, then you may draw His likeness, and show it to anyone willing to contemplate it. (Emphasis supplied)
Depict His ineffable condescension, His virginal birth, His baptism in the Jordan, His transfiguration on Thabor, His all-powerful sufferings, His death and miracles, the proofs of His Godhead, the deeds which He worked in the flesh through divine power, His saving Cross, His Sepulchre, and resurrection, and ascent into heaven. Give to it all the endurance of engraving and colour.
Have no fear or anxiety; worship is not all of the same kind. Abraham worshipped the sons of Emmor, impious men in ignorance of God, when he bought the double cave for a tomb. Jacob worshipped his brother Esau and Pharao, the Egyptian, but on the point of his staff He worshipped, he did not adore. Josue and Daniel worshipped an angel of God; they did not adore him. The worship of latreia is one thing, and the worship which is given to merit another. Now, as we are talking of images and worship, let us analyse the exact meaning of each.

An image is a likeness of the original with a certain difference, for it is not an exact reproduction of the original. Thus, the Son is the living, substantial, unchangeable Image of the invisible God, bearing in Himself the whole Father, being in all things equal to Him, differing only in being begotten by the Father, who is the Begetter; the Son is begotten. The Father does not proceed from the Son, but the Son from the Father. It is through the Son, though not after Him, that He is what He is, the Father who generates. In God, too, there are representations and images of His future acts, – that is to say, His counsel from all eternity, which is ever unchangeable.
That which is divine is immutable; there is no change in Him, nor shadow of change. Blessed Denis (the Carthusian) who has made divine things in God’s presence his study, says that these representations and images are marked out beforehand. In His counsels, God has noted and settled all that He would do, the unchanging future events before they came to pass. In the same way, a man who wished to build a house, would first make and think out a plan. Again, visible things are images of invisible and intangible things, on which they throw a faint light.”
Jesus Christ is “the image of the invisible God.” — Col. 1:15
“Have I been with you all this time, Philip, and you still do not know me? Whoever has seen me has seen the Father. How can you say, ‘Show us the Father’?” (John 14:8–9).