Image-worship or divine honour paid to any created object. Paul describes the origin of idolatry in Romans 1:21-25: men forsook God, and sank into ignorance and moral corruption (1:28).
The forms of idolatry are,
Fetishism, or the worship of trees, rivers, hills, stones, etc.
Nature worship, the worship of the sun, moon, and stars, as the supposed powers of nature.
Hero worship, the worship of deceased ancestors, or of heroes.
In Scripture, idolatry is regarded as of heathen origin, and as being imported among the Hebrews through contact with heathen nations. The first allusion to idolatry is in the account of Rachel stealing her father's teraphim (Genesis 31:19), which were the relics of the worship of other gods by Laban's progenitors "on the other side of the river in old time" (Joshua 24:2). During their long residence in Egypt the Hebrews fell into idolatry, and it was long before they were delivered from it (Joshua 24:14; Ezekiel 20:7). Many a token of God's displeasure fell upon them because of this sin.
The idolatry learned in Egypt was probably rooted out from among the people during the forty years' wanderings; but when the Jews entered Palestine, they came into contact with the monuments and associations of the idolatry of the old Canaanitish races, and showed a constant tendency to depart from the living God and follow the idolatrous practices of those heathen nations. It was their great national sin, which was only effectually rebuked by the Babylonian exile. That exile finally purified the Jews of all idolatrous tendencies.
The first and second commandments are directed against idolatry of every form. Individuals and communities were equally amenable to the rigorous code. The individual offender was devoted to destruction (Exodus 22:20). His nearest relatives were not only bound to denounce him and deliver him up to punishment (Deuteronomy 13:20-10), but their hands were to strike the first blow when, on the evidence of two witnesses at least, he was stoned (Deuteronomy 17:2-7). To attempt to seduce others to false worship was a crime of equal enormity (13:6-10). An idolatrous nation shared the same fate. No facts are more strongly declared in the Old Testament than that the extermination of the Canaanites was the punishment of their idolatry (Exodus 34:15,16; Deuteronomy 7; 12:29-31; 20:17), and that the calamities of the Israelites were due to the same cause (Jeremiah 2:17). "A city guilty of idolatry was looked upon as a cancer in the state; it was considered to be in rebellion, and treated according to the laws of war. Its inhabitants and all their cattle were put to death." Jehovah was the theocratic King of Israel, the civil Head of the commonwealth, and therefore to an Israelite idolatry was a state offence (1 Samuel 15:23), high treason. On taking possession of the land, the Jews were commanded to destroy all traces of every kind of the existing idolatry of the Canaanites (Exodus 23:24,32; 34:13; Deuteronomy 7:5,25; 12:1-3).
In the New Testament the term idolatry is used to designate covetousness (Matthew 6:24; Luke 16:13; Colossians 3:5; Ephesians 5:5).