Celsus believed in the logos that transcended images and idols, so he admits that worshipping mere idols, without understanding the spiritual nature of what an image represented was meaningless. His problem with Christians is that they have no kind of image in their own religion so they are like the Persians who worship ‘no god’ because to Celsus an invisible god is nothing, for the gods must have some physical form, as represented by the images of them:
Let us now see what follows. "Let us pass on," says he, "to another point. They cannot tolerate temples, altars, or images. In this they are like the Scythians, the nomadic tribes of Libya, the Seres who worship no god, and some other of the most barbarous and impious nations in the world. That the Persians hold the same notions is shown by Herodotus in these words: 'I know that among the Persians it is considered unlawful to erect images, altars, or temples; but they charge those with folly who do so, because, as I conjecture, they do not, like the Greeks, suppose the gods to be of the nature of men.' (Origen quoting Celsus)
Celus also admits that philosophers do not confuse the mere ‘wood, brass, or gold’ with the actual god but are merely ‘representing the Divine Being.’ It is this refusal to allow physical objects as something to represent the Divine being that most infuriates Cesus against the Christians. Furthermore, not only so but Christians in their rejection of worshiping the one and true invisible God with images actually believe that the Greeks who use images actually only facilitate a worship of demons through them.
Heraclitus also says in one place: 'Persons who address prayers to these images act like those who speak to the walls, without knowing who the gods or the heroes are.' And what wiser lesson have they to teach us than Heraclitus? He certainly plainly enough implies that it is a foolish thing for a man to offer prayers to images, whilst he knows not who the gods and heroes are. This is the opinion of Heraclitus; but as for them, they go further, and despise without exception all images. If they merely mean that the stone, wood, brass, or gold which has been wrought by this or that workman cannot be a god, they are ridiculous with their wisdom. For who, unless he be utterly childish in his simplicity, can take these for gods, and not for offerings consecrated to the service of the gods, or images representing them? But if we are not to regard these as representing the Divine Being, seeing that God has a different form, as the Persians concur with them in saying, then let them take care that they do not contradict themselves; for they say that God made man His own image, and that He gave him a form like to Himself. However, they will admit that these images, whether they are like or not, are made and dedicated to the honour of certain beings. But they will hold that the beings to whom they are dedicated are not gods, but demons, and that a worshipper of God ought not to worship demons." (Origen quoting Celsus)
Although later church history would show otherwise concerning the use of images in worship, Origen admitted that Christians were ‘exactly like Jews’ in this rejection of all graven images:
But Christians and Jews have regard to this command, "Thou shalt fear the Lord thy God, and serve Him alone;" and this other, "Thou shalt have no other gods before Me: thou shalt not make unto thee any graven image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth: thou shalt not bow down thyself to them, nor serve them;" and again, "Thou shalt worship the Lord thy God, and Him only shalt thou serve." It is in consideration of these and many other such commands, that they not only avoid temples, altars, and images, but are ready to suffer death when it is necessary, rather than debase by any such impiety the conception which they have of the Most High God. (Origen)
The reason why Origen thinks an image has no place in the worship of God is that he says God is invisible and so we must shut our physical eyes to worship him in spirit and truth. He calls this using the yes of the soul:
But a Christian, even of the common people, is assured that every place forms part of the universe, and that the whole universe is God's temple. In whatever part of the world he is, he prays; but he rises above the universe, "shutting the eyes of sense, and raising upwards the eyes of the soul." And he stops not at the vault of heaven; but passing in thought beyond the heavens, under the guidance of the Spirit of God, and having thus as it were gone beyond the visible universe, he offers prayers to God. (Origen)
All true Christians therefore have the eye of the mind sharpened, and the eye of sense closed; so that each one, according to the degree in which his better eye is quickened, and the eye of sense darkened, sees and knows the Supreme God, and His Son, who is the Word, Wisdom, and so forth. (Origen)
Conclusion: Therefore being that God is invisible Origen defends Christianity for not using images by saying we really need to shut our eyes, not use physical things to help our thoughts, but deny such use of icons and images in the pure worship of God. In this way we can see with the eyes of the mind and soul.