God is Righteous (1:18-20)
The Roman listener and reader would not have had the same reference point as the Jewish believer. So Paul begins with his own version of the creation story from Genesis 1 [vv. 19-20]. Paul speaks to the creation and all that is in it to demonstrate that God is good, but more importantly that God is righteous. The word righteous tells us something about the way that God lives out his existence. Everything we need to know about God is made knowable by virtue of God’s creation. What we see is the evidence that points to and illustrates for us who God is. And God is righteous and therefore stands up against all “ungodliness and unrighteousness of men” [v. 18].
God is Denied (1:21-25)
Paul then makes a move toward describing the state of those that forget to look at God, or more specifically, that intentionally turn away from looking at God. This is where Paul begins to lay the foundation that he will expand in Romans 5:12. What is important here is to understand what Paul is describing. God will suffer the reproach of man only for a time. But the longer we persist in denying God, Paul tells us that God will eventually give us up.
So God abandoned them to do whatever shameful things their hearts desired. As a result, they did vile and degrading things with each other’s bodies. They traded the truth about God for a lie. So they worshiped and served the things God created instead of the Creator himself, who is worthy of eternal praise! Amen. [Romans 1:24-25, NLT]
Whenever we lose sight of God, when we forget to honor God for who and what he is we tempt God and become subject to God’s judgment. What we have to consider is this: Is there any greater judgment than to be left to oneself?
God is NOT Mocked (1:26-32)
Then Paul closes by illustrating the manifestation of Sin in the practice of sins. I don’t believe that Paul is saying that all will perform these sins. I think this is where many people begin to dismiss the doctrine of Total Depravity. We have to see that Total Depravity is not about the depth of sin, but rather about the culpability of sin and capability of sinning. We all, as sons and daughters of Adam and Eve, have become partakers in Sin. We are born in Sin [Psalm 51:5] and we are guilty of our own transgressions [Romans 3:23]. What I hear Paul saying is that once the path of selfishness and idolatry is chosen there is no means of predicting the depths to which one can fall. I find this to be the major thrust of this section and starting block for what is to come in the following chapters.