Definition and Nature of Idolatry:
Idolatry, in biblical terms, refers to the worship of idols or the excessive reverence for or devotion to anything other than the one true God. It is considered a grave sin in the Judeo-Christian tradition, as it directly violates the first two commandments given by God to Moses: "You shall have no other gods before Me" and "You shall not make for yourself an idol" (Exodus 20:3-4).

Biblical Instances and Warnings:
Throughout the Bible, idolatry is depicted as a recurring temptation and a significant cause of Israel's downfall. The Israelites frequently turned to the gods of surrounding nations, despite repeated warnings from prophets and leaders. For instance, in 1 Kings 18, the prophet Elijah confronts the prophets of Baal, demonstrating the futility of idol worship and reaffirming the supremacy of Yahweh.

The New Testament continues to warn against idolatry, expanding its definition beyond physical idols. The Apostle Paul admonishes believers to "flee from idolatry" (1 Corinthians 10:14) and equates greed with idolatry in Colossians 3:5, indicating that anything that takes precedence over God in one's heart can become an idol.

Characteristics of Idolatry:
1. Substitution of God: Idolatry involves replacing God with something else, whether it be a physical object, a person, or an abstract concept. This substitution is a direct affront to God's sovereignty and exclusivity as the object of worship.

2. Misplaced Trust: Idolatry often involves placing trust in created things rather than the Creator. Isaiah 44:9-20 vividly describes the absurdity of idol-making and the folly of trusting in man-made objects.

3. Heart's Devotion: Idolatry is ultimately a matter of the heart. Ezekiel 14:3 speaks of idols set up in the heart, indicating that idolatry is not merely an external act but an internal disposition that prioritizes something above God.

Consequences of Idolatry:
The Bible consistently portrays idolatry as leading to spiritual and moral decay. In Romans 1:21-23, Paul explains how idolatry results in futile thinking and darkened hearts, as people exchange the glory of the immortal God for images resembling mortal beings. This exchange leads to a host of sins and societal breakdowns.

God's Response to Idolatry:
God's response to idolatry is one of righteous jealousy and judgment. The prophets frequently warned of impending judgment due to the people's idolatrous practices. Yet, God also extends grace and calls for repentance. In 1 John 5:21, believers are urged to "keep yourselves from idols," highlighting the ongoing need for vigilance and devotion to God alone.

Practical Identification of Modern Idolatry:
In contemporary contexts, idolatry may not always involve physical idols but can manifest in various forms such as materialism, career obsession, or the idolization of relationships. Believers are called to examine their lives and hearts, ensuring that nothing takes precedence over their relationship with God. As Jesus taught, "You cannot serve both God and money" (Matthew 6:24), emphasizing the need for undivided loyalty to God.

Conclusion:
While the forms of idolatry may have evolved, the core issue remains the same: anything that usurps God's rightful place in our lives constitutes idolatry. The Bible calls for a wholehearted devotion to God, recognizing Him as the sole object of worship and trust.