De la AAC.ASE.Wiki
Questions always arise as to whether the use of Catholic Symbols is really a form of idolatry. Usually it is because the questioner isn't altogether familiar with what these symbols really are. We don't worship the crucifix. We use it as a reminder of Jesus suffering and death for our sins. We do not worship the fish. We display it as being a proud emblem in our Christianity. We don't worship the statues of the saints. We use them to point out their wonderful lives so they might be role-models for all of us to emulate.
Dating back to when the Ten Commandments were given to Moses, idolatry in the Old Testament was defined as the worship of idols or images. It is the worship of not God that's wrong and sinful. The mere images, symbols or icons are not the problem.
An excellent example of this in the duration of Moses is the Brass Serpent. God commanded Moses to make this Brass Serpent and lift it high to cure any Israelite who checked out it of snakebites. I repeat it was God who commanded Moses to make this image. Later ever, King Hezekiah destroyed the Serpent since the Hebrew people have been burning incense into it in worship. The symbol had eventually be an object of idolatry. See the difference?
When God gave commandments regarding idolatry he meant so that it is understood in the most literal form. According to the Bible, most idolaters really thought that their idols were gods. That is not so today with Catholic Symbols.