Exodus 20:4
You shall not make for yourself a 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.
One of the things that puzzles many people about the Catholic Faith is how we can have statues or icons in our Church while retaining this commandment in our Bible. The answer is found in the mystery of the Incarnation. The constant temptation of paganism was to confuse things which remind us of God with God himself. And so a whole host of creatures was worshiped by pagan antiquity (and by modern post-Christian paganism). But, as C.S. Lewis remarks of Israel, it was the destiny of that nation to be turned from the likeness to the Reality. And so, all short cuts (like physical images) were denied them by this commandment, because they were being prepared, not for the revelation of a God without an image, but for the revelation of Jesus, who is the true “image of the invisible God” (Col 1:15). When that image came and God stamped his likeness on the human face of Jesus, the prohibition was transfigured. It is still true that no image can be worshiped. But it is even truer that images are now a participation in the light of God, shining through the Incarnate God who is Jesus Christ. Saints, who are members of his body, are now windows into God, not barriers to his light or cheap Brand X substitutes for his glory. Therefore, in honoring their images (not worshipping them), we honor (not worship) the saints they represent and in honoring the saints, we honor their Lord, who is the True Image of God.