Idolatry, in monotheistic traditions, is the worship of something or someone other than God in place of God. It is the substitution of symbols from everyday life for the growing, evolving, progressing concepts, sentiments and ideals which should inspire human society and individuals. Idolatry may take the overt form of the worship of, for instance, the sun, a king, an animal, or a statue. It may be less overt in the sense of an object of devotion and desire which is seen as the ultimate source of good and reason for living. Nationalism or materialism or even extreme forms of family devotion can be classed as idolatry in this sense.
The concept of idolatry originated in the very specific historico-religious context of the monotheism of Israel. In the applications of Second Commandment, it acquired definitive formulation in censure by the prophets of Israel of the pagan cults and their influence on the chosen people. This biblical heritage passed into the New Testament and early Christianity. The monotheism of Islam adopted this Judaeo-Christian concept and made it one of the foundations of its belief and its faith.
There is a long tradition of incorporating gargoyle-like figures into major structures, especially cathedrals. In 1989, a troll-like figure was incorporated into the structure of San Francisco's repaired Bay Bridge (following its partial destruction by earthquake) in order to enhance future safety. It has been argued that certain contemporary belief systems can encourage idolatry -- such as when Judaism is perceived as a corporate obsession with the idolatries that vie for the loyalty of a people chosen to serve a jealous God and when for Jews both socialism and Zionism become such idols.
Idolatry is the worship of the creature instead of the Creator and, to make matters worse, the creature is made by man, who is himself a creature. Idolatry is, also, the worship of what in modern terms is process, the life-force, the 'elan vital' or what we will, instead of the Creator who transcends and is in some sort external to creation. Finally, idolatry is the worship of an idol considered as a substitute for the divine.