Aren't you the one who has told us that (bold/underline mine):
"The second is the Patriarchal administration. It was the time after the fall from the Garden of Eden, but before the Law was given. This second administration ended with the coming of the Law to Moses.
...
These different administrations are suited to different times because God has spoken everything to its proper time and administration. We will never understand the truth of God’s Word if we read into one administration what God tells us belongs to another administration. If we believe what God said in one administration and carry it into another administration that was on a different principle, we will be taking what is true for one time, and using it to contradict what is also true for another time. When we mix them all together, by jumbling the whole Bible together: Law, Gospel, Grace, Judgment, Glory, Jew, Gentile, and the Church of God, we will be very confused in our understanding of the truth of God’s Word."
So you want to take a truth that was written to a certain time period, apply it to yourself, and thereby do exactly what you warn is not to be done.
Not only that, but those who lived during the time before Moses received not the promise (Heb 11:39). So if you are going to apply Rom 5:13 to yourself, do you take on the whole of what was available in the time period before Moses, when what is available in our day and time is the fullness of all that the Lord Jesus Christ provides for us NOW? Just something for you to think about ...
We are wholly incapable of "changing [ our ] mind".
In Romans 12, we are instructed to present your bodies a living sacrifice to God (vs 1) and be not conformed to this world (vs 2). That's our part.
Then, we are transformed by the renewing of your mind (vs 2). That's God's part. The word "transformed" is the verb ... the action. And in the Greek this verb is passive which means the subject (the believer) is the recipient of the action. And God transforms us by the renewing of your mind. And the renewing of your mind is a noun.
So, understanding the verbs in Rom 12:1-2, Who is it that changes our mind from "carnal" to "the mind of Christ" (1 Cor 2:16)? Is it us? Or is it God? I'll go with God. He is much more capable of effecting the change than I am.
If I do the changing, it is nothing more than going from one carnal thought to another ... all the while thinking I am going from worse to better. carnal is carnal.
Yes, you have explained this process more than once.
In Ephesians 4:22 we are instructed to put off concerning the former conversation, the old man. This is something we do.
In verse 23, it says and be renewed in the spirit of your mind. This "renewed" is a verb. However, it is passive ... which means the subject (the believer) is the recipient of the action.
So as we "put off the old man", we are the recipients of the renewed in the spirit of your mind. Again, the renewal of our mind is what is received when we put off the old man.
Then verse 24 ... and that ye put on the new man.
Now, getting back to your point that the noun of Rom 12:2 is the same as the verb in Eph 4:23. Why not just let Rom 12:2 be as God intends and let Eph 4:23 be as God intends? Isn't that a more worthy endeavor than changing God's Word to conform to an idea we think is good? To me, replacing Rom 12:2 with Eph 4:23 is not good workmanship.
2 Timothy 2:15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.