They point out that they do not worship graven images, that they use the graven images as reminders, and it is backed up by Scripture.
"David gave Solomon the plan "for the altar of incense made of refined gold, and its weight; also his plan for the golden chariot of the cherubim that spread their wings and covered the ark of the covenant of the Lord. All this he made clear by the writing of the hand of the Lord concerning it all, all the work to be done according to the plan" (1 Chr. 28:18–19). David’s plan for the temple, which the biblical author tells us was "by the writing of the hand of the Lord concerning it all," included statues of angels."
Similarly Ezekiel 41:17–18 describes graven (carved) images in the idealized temple he was shown in a vision, for he writes, "On the walls round about in the inner room and [on] the nave were carved likenesses of cherubim."
During a plague of serpents sent to punish the Israelites during the exodus, God told Moses to "make [a statue of] a fiery serpent, and set it on a pole; and every one who is bitten, when he sees it shall live. So Moses made a bronze serpent, and set it on a pole; and if a serpent bit any man, he would look at the bronze serpent and live" (Num. 21:8–9).
One had to look at the bronze statue of the serpent to be healed, which shows that statues could be used ritually, not merely as religious decorations.
Catholics use statues, paintings, and other artistic devices to recall the person or thing depicted. Just as it helps to remember one’s mother by looking at her photograph, so it helps to recall the example of the saints by looking at pictures of them. Catholics also use statues as teaching tools. In the early Church they were especially useful for the instruction of the illiterate. Many Protestants have pictures of Jesus and other Bible pictures in Sunday school for teaching children. Catholics also use statues to commemorate certain people and events, much as Protestant churches have three-dimensional nativity scenes at Christmas.
If one measured Protestants by the same rule, then by using these "graven" images, they would be practicing the "idolatry" of which they accuse Catholics. But there’s no idolatry going on in these situations. God forbids the worship of images as gods, but he doesn’t ban the making of images. If he had, religious movies, videos, photographs, paintings, and all similar things would be banned. But, as the case of the bronze serpent shows, God does not even forbid the ritual use of religious images.
It is when people begin to adore a statue as a god that the Lord becomes angry. Thus when people did start to worship the bronze serpent as a snake-god (whom they named "Nehushtan"), the righteous king Hezekiah had it destroyed (2 Kgs. 18:4).
Sometimes anti-Catholics cite Deuteronomy 5:9, where God said concerning idols, "You shall not bow down to them." Since many Catholics sometimes bow or kneel in front of statues of Jesus and the saints, anti-Catholics confuse the legitimate veneration of a sacred image with the sin of idolatry.
Though bowing can be used as a posture in worship, not all bowing is worship. In Japan, people show respect by bowing in greeting (the equivalent of the Western handshake). Similarly, a person can kneel before a king without worshipping him as a god. In the same way, a Catholic who may kneel in front of a statue while praying isn’t worshipping the statue or even praying to it, any more than the Protestant who kneels with a Bible in his hands when praying is worshipping the Bible or praying to it.
http://www.catholic.com/library/Do_Catholics_Worship_Statues.asp
