The Jews were forbidden to have images under the Old Covenant (with a few exceptions). The reason for this was that the temptation to worship the image was strong for them. But, as C. S. Lewis says, it was the destiny of that people to be turned from the thing that resembled God to God himself. When God the Son becomes incarnate and becomes the express image of the invisible God (Heb 1:3), our relationship to images changes. The prohibition of images is discovered to be provisional until the true incarnate Image appears. Images are now permissible since God himself has become a kind of image in Christ. Thus our images of God are now windows into his Incarnation rather than fertility images, figments of our imagination, or idols. We do not worship images. We see through them to the Incarnate God and his saints, who are also images of Christ.