Idolatry is the worship of false gods. Judaism, Christianity, and Islam are monotheistic religions, which means that they support belief in only one God; polytheistic religions support belief in many gods or goddesses. The Ten Commandments prohibit polytheism, which is considered a grave and serious sin.
One of the most common forms of idolatry has been the worship of idols themselves. Pagan religions of antiquity worshipped the sun, the moon, the sky, the earth, wind, fire, and the sea as deities. Many polytheistic religions also worship statues and idols as being divine.
Whenever the Hebrew people in the Old Testament dabbled in the idolatry promoted by their neighbors, God would severely punish them. Canaanites, Babylonians, Assyrians, and other ancient peoples practiced some form of Baal worship, which involved a statue of the god and usually some form of ritual prostitution. The Egyptians, Greeks, and Romans were famous for their myriad of idols to their false gods.
Not every statue or image is an idol, however. Idols are graven images intended for worship. Washington, D.C., is punctuated with statues of George Washington, Thomas Jefferson, Ben Franklin, and Abraham Lincoln. We do not worship those statues or the men they represent, so they are not considered idols. Similarly, statues and pictures (also called icons) of historical people in religion are not idols if no one worships them. If these sculptures and images are mere reminders of holy people in the past, then no one is violating the Commandment against idolatry.
Jewish custom, however, was that no image of God was ever to be made and His proper, sacred name could only be spoken once a year on the Day of Atonement, Yom Kippur. Early Christians, being mostly converts from Judaism, were hesitant and squeamish about making any image of Christ, even though they professed their belief that He was human and divine and that in his divine personhood, he deserved the same worship and adoration reserved for God alone.
Only after Christianity was legalized in 313 by the Roman Emperor Constantine, with his Edict of Milan, did Christians begin to portray Jesus and His mother, the Virgin Mary, in sacred art. Purists would condemn these things as being graven images, and accuse those who had them of being guilty of idolatry.
Catholics, however, do not worship the statues, icons, images, or the many saints depicted in them, including the mother of Jesus. These items are akin to the photos of loved ones, living and deceased, that people today keep in their wallets, in their purses, and in their homes.
Iconoclasm (from the Greek eikonoklasmos) literally means “the breaking of icons.” Icons are images of God or of any saint, painted onto square or rectangular pieces of wood. They depict either holy people like the saints, or holy events from the Bible (like the miracles of Jesus) or holy occasions (like the Assumption of Mary into heaven). Iconoclasts, then, are those who would promote the destruction of all images of God or the saints.
Judaism and Islam are not the only religions with a strong and absolute prohibition of any type of images, whether of holy people or of God Himself. Certain factions of Christians have historically held similar views that not only are false gods not to be memorialized into stone or metal, but neither can the One True God.
Emperor Leo III (717–741) was a Byzantine Emperor of the East and a staunch iconoclast who advocated and ordered the smashing of all icons, be they pagan idols or Christian images of devotion. The common people and the monks of the monasteries (the ones who actually painted the Christian icons for use in church or at home) did not share the Emperor’s zeal and conviction that any and all icons were evil. Many of the peasants and lower clergy (below the rank of patriarch or bishop) popularized icons because they helped them remember holy people or holy themes. Just as stained glass in the Middle Ages of Western Europe was first used as the common catechisms for the illiterate lower classes of the day, icons in the Eastern Byzantine Church were used likewise.
The Catholic Encyclopedia says, “Persecution raged in the East. Monasteries were destroyed, monks put to death, tortured, or banished. The iconoclasts began to apply their principle to relics also, to break open shrines and burn the bodies of saints buried in churches.” It took an ecumenical council, Nicea II, summoned by the Empress Irene in 787, to officially condemn as heresy the notion of iconoclasm.