In a general sense, idolatry is the paying of divine honor to any created thing or the ascription of divine power to natural agencies.^^
There are two main Bible passages that speak to idolatry, one from the Old Testament, and one from the New Testament. Although there are other relevant passages, Exodus lays down the foundation for all other discussions of idolatry, and Romans lays down the New Testament "expansion."
Exodus 20:2-6 “I am the LORD your God, who brought you out of Egypt, out of the land of slavery. You shall have no other gods before ?me. You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them; for I, the LORD your God, am a jealous God, punishing the children for the sin of the fathers to the third and fourth generation of those who hate me, but showing love to a thousand generations of those who love me and keep my commandments. ^^
Romans 1:18-25 ?"The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles. Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator—who is forever praised. Amen. ^^
However, idolatry has never been merely limited to external, graven images alone. For instance, in Ezekiel, the Lord says that "these men have set up idols in their hearts." This points to the heart as the focus of obedience and sin - just as the commandment "Thou shall not covet..." and emphasizes to us that the Lord is even more concerned with what goes on in our hearts than the external appearances of our lives.
Ezekiel 14:3 "“Son of man, these men have set up idols in their hearts and put wicked stumbling blocks before their faces. Should I let them inquire of me at all?" ^^
- Why Idolatry Was (and Is) Attractive, by Kevin DeYoung