aChristian...
I believe you are close to the truth. But, I think it is even simpler as Romans 5 brings out.
Rom 5:20
20 The law was added so that the trespass might increase.
Most think that the "law" referred to in Romans 5 is the Mosaic Law. I believe that understanding to be erroneous. The whole context of Romans 5 from verse 12 on is about Adam and his plight, and the contrast with Jesus and his redeeming.
That mistaken understanding comes from here:
Rom 5:12-14
12 Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all men, because all sinned- 13 for before the law was given, sin was in the world. But sin is not taken into account when there is no law. 14 Nevertheless, death reigned from the time of Adam to the time of Moses, even over those who did not sin by breaking a command, as did Adam, who was a pattern of the one to come.
Just because verse 14 mentions Moses in a timespan, people incorrectly understand the law in verse 13 to be the Mosaic Law. That is wrong. Why? Verse 12 and the beginning of verse 13 are the same sentence. The context of a sentence never changes in the middle. The context in the beginning of the sentence is about Adam, so the law at the end of the sentence has to be about Adam. Adam only had one law, the law of the tree. That law Paul is talking about is the law of the tree. Also, Adam had nothing to do with the Mosaic Law, ever. Why would anyone bring in the Mosaic Law into a discussion about Adam's sin? Again:
Rom 5:20
20 The law was added so that the trespass might increase.
There's and old saying, "Laws were meant to be broken." Satan was a corrupting influence...Adam and Eve were going to get soiled regardless of how "Good" a creation they were. The law of the tree was meant to be broken, so sin would increase.
Now, let's look at it closer:
Rom 5:12-14
12 Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all men, because all sinned- 13 for before the law was given, sin was in the world.
BEFORE the law of the tree was given, sin was already in the world. How can that be if nothing was eaten yet? Satan was already on his sinful rampage in the heavens. But why didn't God destroy Satan right away and stop the corrupting influence?
Rom 5:13
But sin is not taken into account when there is no law.
There were never any laws in heaven. There was never any bad in heaven. When there is no bad there is no law as law is put in place when bad EXISTS.
OK. So bad now exists in heaven as Satan is in sin. Bad is in heaven for the first time. Why couldn't God make a law in heaven against what Satan was doing, before Adam and Eve, so that he could be destroyed before he corrupted?
I believe it has to do with Satan's sinful claim, "I am a god." That was and is a very real claim. A claim that was real to the Creator. What was the definition of God in the heavens? What constitutued being god? Could a spirit creature claim independent godship for himself and not have any repercussion from the Creator? Well, there was no law against it...as a matter of fact there was NO LAW PERIOD!!
Since Satan sin began claiming his godship, the Creator had to deal with Satan how? As another god. A false god, but a god just the same. Can one god make law on another god? How about this...in order for Satan to die, he had to be guilty of a law that would convict him to death....
Again the Bible is IMPLICIT:
Rom 4:14-15
15 because law brings wrath. And where there is no law there is no transgression.
Law brings wrath. ANY LAW. ALL LAW. Why? Because they will be broken...Again the Bible says, where there is no law, there is no transgression. Satan was free to claim godship, because there was no law.
The battle in the beginning was the true God (Creator) against a false god (Satan), and the Creator's plan to rid the creation of a false god. It had to be done legally with justice in wisdom.