Sin, when we boil it down, is rooted in selfishness. Sin, in its essence, is the worship of self. It doesn’t look to the heart and desires of God; rather it seeks our own needs.  

As Paul begins Romans, he exposes our self-worshiping hearts. He exposes the hearts that have been given over to worship the created rather than the Creator. He exposes the sin that has been given over to passions and lusts. 

For although they knew God, they did not honor Him as God or give thanks to Him, but they became futile in their thinking, and their foolish hearts were darkened. Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things. 

Therefore God gave them up in the lusts of their hearts to impurity, to the dishonoring of their bodies among themselves, because they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever! Amen.  - Romans 1:21-25

Luther wrote: 

"They worshiped Him not as God but in the likeness of an image, and so they worshiped not God but a figment of their own imagination. How many people are there even today who worship God not as God but as something that they have imagined in their own hearts? 

Just look at all our strange, superstitious practices, products of utter vanity. 

We can also simply say: “They did not honor Him as God,” that is, they did not honor Him as it was fitting for them to render to Him honor and thanks. Look at the order and the various levels of perdition: 

The first level is ingratitude, or the omission of gratitude. Self-satisfaction is responsible for this, for it takes pleasure in things received as though they were not received at all, and it leaves the Giver out of consideration. 

The second level is vanity. One feasts on oneself and on all of creation and enjoys the things that bring profit. Thus one becomes of necessity vain “in his thoughts,” that is, in his plans, endeavors, and ambitions. For whatever one seeks in and through these gifts is completely vain. One seeks only himself, that is, one’s own glory, delight, and advantage. 

The third level is blindness. A person becomes necessarily blind in his whole heart and in all his thoughts, because he has turned completely away from God. Since he is then lodged in darkness, what else can he do except the things for which an erring man or a fool strives? For a blind man errs very easily, yes, he errs all the time. 

And so the fourth level is the error over against God. 

This is the worst. It leads directly to idolatry. To have arrived at this point means to have arrived at the abyss. For when a person has lost God, nothing remains except that he be given over to every type of turpitude according to the will of the devil. The result is that deluge of evils and blood-letting of which the apostle goes on to speak in the following passages. 

By the same steps people also today arrive at spiritual idolatry of a more refined type, which at present is widespread. Here they worship God not as He is but as they imagine and think Him to be. 

From this text we may therefore deduce that if someone surrenders to these passions, it is a sure sign that he has left the worship of God and has worshiped an idol, or he has turned the truth of God into a lie (cf. Romans 1:25). Those who do not “see fit to acknowledge God” (Romans 1:28) are branded in this way, that they are permitted to fall into all kinds of vices. 

It is bad enough to change the glory of God into the likeness of an image. This is the sin of blindness, of lack of knowledge, or of an erring heart. But it is still worse if one does not only err in this way but in the perversion of one’s heart also worships those images and adores a creature. 

And as they have not glorified God, neither in their hearts nor in their actions, but have instead transferred His glory to something else and have thus become filled with shame in their hearts, so it is only fair that they should also bring shame upon their own bodies and likewise upon others on their bodies." 

Operating the Elevators of Idolatry

If you’re anything like me, when you read these words from both Paul and Luther, you can watch yourself go up the elevator from ingratitude to vanity to blindness to idolatry. 

I’ll arrive on the first floor without much thought, especially when life is good. The moment things are going well, I like to take credit. The promotion, my kids' good behavior, the compliments from my wife—they say something about me. My house—I work hard for it. My sermon—I nailed it. My family—I sacrifice everything for them. Notice what happens when you start your journey toward idolatry: you become the subject of all the verbs. You’re the one doing the work. You’re the one deserving the credit. You’re the giver, everyone else is the recipient.

@@A lack of gratitude is just an early indicator that you think you’re god.@@ 

The second floor doesn’t take long to reach once you’ve explored the first. When I have no need for gratitude, vanity is the natural overflow. Vanity looks for the glory and the fame and the renown. It’s the desire that all things point to your own greatness. 

The third floor is when you stop seeing. Blindness makes you ignorant to the call of Jesus. Blindness misses the fact that you are called child of God and ignores the life that Jesus calls you to. 

The fourth level is idolatry. It’s when your fear, your love, and your trust clings to something other than Christ. It’s when your identity is wrapped up in you, your accomplishments, and your stuff. It’s when you cling to your own work instead of Christ’s work on the cross. 

There’s not one of us who isn’t familiar with these floors. We could be the elevator operators, sending people up to the floors of all the sinful places we have been to. 

This is why Luther wrote, "The apostle is interested to show that all were sinners and needed the grace of Christ." 

When God exposes our elevator climb towards idolatry, we will find all the ways we've abandoned our worship of God for the worship of something inferior. As God exposes our hearts, we will find our faulty trust and hope in a god that never saves. Yet it's even in that exposing work that Jesus comes to us exposing to us something greater - an identity not wrapped up in our own work, but an identity wrapped up in the work of Jesus.