Will God allow our disobedience and idolatry to go unpunished?
No, every sin is against the sovereignty, holiness, and goodness of God, and against his righteous law, and God is righteously angry with our sins and will punish them in his just judgement both in this life, and in the life to come.
For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God. Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.
Ephesians 5:5-6
We live in a culture where punishment is perceived to be uncompassionate and even inhumane. Sociologists have decried strict prison sentences and increasingly emphasized ‘harm-reduction’ and liberalization of drug laws, all with the intent of pushing this idea: you can compel people more with a carrot rather than a stick. This is not necessarily an unbiblical idea — our desire for reward can truly be more compelling for us than our fear of punishment. The promise of scripture stands: ‘Delight yourself in the LORD and he will give you the desires of your heart’ (Ps 37:4); ‘In your presence there is fullness of joy – at your right hand are pleasures forevermore’ (Ps 16:11). However, by itself it is an incomplete biblical idea. Scripture is exceedingly clear: there is not just a carrot – there is also a stick. If you live according to biblical precepts, you will be rewarded with joy beyond measure – despite the appearances of your circumstances. Live according to the evil ways warned about, and punishment is promised to come your way. The book of Revelation speaks of this foreboding scene in stark terms:
And I saw the dead, great and small, standing before the throne, and books were opened. Then another book was opened, which is the book of life. And the dead were judged by what was written in the books, according to what they had done. And the sea gave up the dead who were in it, Death and Hades gave up the dead who were in them, and they were judged, each one of them, according to what they had done. Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. And if anyone's name was not found written in the book of life, he was thrown into the lake of fire.
Revelation 20:12-15 (ESV)
Biblical scenes like this tend to upset a certain modern sentiment in us. Our skepticism is inclined to ask: Isn’t God a forgiving God? Why should he judge anyone according to their works? Why won’t he just let us off with a pass? And yet Scripture is clear. This is the ‘bad news’ that precedes the good news that is the Gospel. We have no choice but to acknowledge the evil state of our own sinful hearts and the just punishment owed to us. When we acknowledge our sin, we are also acknowledging that God is right in passing judgement on us for our sins. If we think we can acknowledge our sins and then somehow God should just overlook them, we have failed to understand the impact of our sins and the holiness of our God. Failure to fear the Lord is the foundational sin, deeply rooted in the heart of the wicked that gives life to every other sin. To fear the Lord is to have a right understanding of God and a right attitude towards him, which leads to right action.
However, the story doesn’t end there. No, God will not allow our disobedience or idolatry to go unpunished, but in His eternal glory he provided a way. He is both Just and Justifier (Rom. 3:26). Jesus pays the penalty that we rightly deserve, and we get the reward that rightly belonged to Him.