Beware lest there be among you a man or woman or clan or tribe whose heart is turning away today from the LORD our God to go and serve the gods of those nations. Beware lest there be among you a root bearing poisonous and bitter fruit, one who, when he hears the words of this sworn covenant, blesses himself in his heart, saying, ‘I shall be safe, though I walk in the stubbornness of my heart.’ This will lead to the sweeping away of moist and dry alike. (Deuteronomy 29:18–19, ESV)
Idolatry is bitter, and bears poisonous fruit like wormwood. It is “a root of bitterness” we get when we turn away from the covenant and “walk in the stubbornness of my heart.” When we turn away from His Law, we turn from justice or the fruit of righteousness to bitter wormwood and cast down righteousness to the earth (Amos 5:7, 6:12).
Idolatry is “cheating” on God. We cheat Him with less than whole-hearted commitment. In public, we might claim to be like loyal spouses and do what God says. But when we ignore His Word it’s just like cheating on a spouse. Any thought or action that doesn’t match His Word is idolatry. Or adultery.
We might comfort ourselves that we are not idolaters because we don’t have a statue in the living room (let’s overlook the crucifix, Christmas tree, Easter eggs and bunnies for now). But idolatry is not limited to actual images. Paul says that covetousness is idolatry (Ephesians 5:5). God says the Chaldeans worship their own might (Habakkuk 1:11) and Jesus says that Mammon or money (Luke 16:13) is a god. And don’t even get me started on American Idol. If we reject His ways and go our own way, even in the smallest thing, it’s idolatry.
From the book Whole Bible Christianity