"To whom then will you liken God? Or what likeness will you compare to Him? The workman molds an image, The goldsmith overspreads it with gold, And the silversmith casts silver chains. Whoever is too impoverished for such a contribution chooses a tree that will not rot; He seeks for himself a skillful workman To prepare a carved image that will not totter. Have you not known? Have you not heard? Has it not been told you from the beginning? Have you not understood from the foundations of the earth? It is He who sits above the circle of the earth, and its inhabitants are like grasshoppers, Who stretches out the heavens like a curtain, And spreads them out like a tent to dwell in. He brings the princes to nothing; he makes the judges of the earth useless. Scarcely shall they be planted, scarcely shall they be sown, Scarcely shall their stock take root in the earth, When He will also blow on them, And they will wither, And the whirlwind will take them away like stubble. “To whom then will you liken Me, or to whom shall I be equal?” says the Holy One." (Isaiah 40:17-25)
The Prophet Isaiah articulates a sharp contrast between the living God and powerless idols carved by the hands of men. It is irreverent to the utmost for us to even compare His unfathomable glory to relics which are the product of our fragile minds. These works are the antithesis of God's majesty. So it is not proper at all for Roman Catholics to use religious iconography to worship Jesus Christ. He is God in the flesh (Colossians 2:9; Hebrews 1:3).
Some have appealed to Christ's incarnation to justify the use of images in worship (CCC # 2129-2131), although it is difficult to see how or why such validates this practice. Saints are human beings, and the Old Testament emphatically condemned making statues of them for the purpose of religious devotion. The Lord became angry with the Israelites who had urged Aaron to make a golden calf as a result of their desire to have a physical representation of God (Exodus 32:8). We cannot even determine exactly what Christ looked like. We are not to worship our God in the manner that the pagans do with their false gods:
"And you shall destroy their altars, break their sacred pillars, and burn their wooden images with fire; you shall cut down the carved images of their gods and destroy their names from that place.” You shall not worship the LORD your God with such things." (Deuteronomy 12:3-4).