“…For the judgment which came from one offense resulted in condemnation, but the free gift which came from many offenses resulted in justification…
For as by one man’s disobedience many were made sinners, so also by one Man’s obedience many will be made righteous…
… as sin [dominated] in death, even so grace might [control] through righteousness to eternal life through Jesus Christ our Lord.”
First. A quick clarification on terms. “Justification” in verse 16 is about the Father, in the position of Judge and Governor of the Universe He created, publicly declaring that a person is righteous in His sight. Since, in God’s sight, in context is about His rules and commands, then such a declaration is saying: “this person “x,” is a person whose thoughts and actions value God above all other things, in accordance to God’s commands and precepts.” This is the gift of Christ, given to all His elect brethren. God gave our sin to Jesus, and Jesus was punished as if He did the sin. And reversely, God freely gave Jesus’ righteousness to us, and relates to us as if we lived it.
Second. Verse 19 is about a pragmatic application. Being made a sinner is about, being created by God’s power (or molded like clay) to be a person who actively/pragmatically acts like a sinner because they are a dirty, sinner. They malfunction when brought into contact with God’s commands. God credited Adam’s sin to all others. Thus, the foundation is that God the ultimate judge declares, person “x” is a disobedient, broken sinner. Then from this proceeds God using His power to mold this person into a sinner, the sinner he declared them to be in Adam. Or that is, God molds them into a defective water jar. Because they are a defective water jar, then when God pours water into them (brings them into contact with His commands) they act broken, because they are broken and defective. God the judge, then judges them guilty for not being able to “in application” hold water (disobeying His commands). It is the reverse for God’s elect Child. God’s mold them into a perfectly made water jar, with no defects. Then, when God pours water into them, they function (in faith obeying God) correctly. God praises and rewards them for pragmatically functioning in a correct way. Or that is, God says believe my promise for healing. God pours this water of His truth into them. Because they have already been re-made into a new creation Christ, they hold (believe) this water correctly. God rewards their faith (functioning correctly) with blessings and healings.
A quick note about sanctification. The Christian sins sometimes, because they believe the lie that they are not already righteous. Or that, the lie that they are not already made as a water jar that is able to hold water. In essence, God pours in the water (His truth), but then Satan and the deceitful lusts of life, convince the Christian to willfully pour it out. The non-Christian is broken, they cannot submit to God’s command to believe. The Christian is already a new creation. They can hold the water, because they are not broken anymore.
Third. Most translations say “ruled” or “reigned” by sin or grace. To make this clearer, I put in  the above terms, which mean the same thing, “controlled” or “dominated.” In fact, the NIV will sometimes translate this as “controlled,” which is a good way to translate it, because some might miss the full weight of the ancient meaning of a King ruling in a Kingdom, with absolute authority. The Roman Centurion in Matthew 8:5-13 understood what ruling in authority means. Since in this same letter to the Romans, Paul shows God’s sovereign control to be like a man molding a clay pot to his own arbitrary whims, then this understanding should apply here as well. Relative to us, there might be secondary objects, but to God there is nothing secondary, relative to His direct control of it. That is, even if man is controlled by demon possession, the demon is ultimately directly controlled by God. That is, God directly controls the demon, like a puppet on string (yet in all fairness to God, the control is much greater), and also, the man, and also all aspects of reality. Yet, the Bible mostly speaks on the relative level. And so, relative from man, he is either dominated by sin, or he is dominated by the power of God’s unmerited favor. Thus, if man is not free on the relative level, how much less so on the ultimate (but that is for another post).
Lastly, the result of being dominated by God’s unmerited favor regards the pragmatic sense. It is having and processing and walking in the exceedingly great life of Jesus Christ. This life is both spiritual life and natural life. It is all joy, peace and righteousness. It is having God as your personal tutor, so that you know the world as it truly is. Thus this life is also, all riches, health and goodness of things. As Jesus is (here and now) a prophet, priest and King, we also who are made in His image, walk as prophets, kings and priests. We are co-heirs with Christ. His public life, is our public life. His spiritual life, is our spiritual life. His natural life, is our natural life. His life is already now and here. Thus, our life in Him is now and here. “Then Jesus said, “Did I not tell you that if you believe, you will see the glory of God, (John 11:40)?”” Martha tried to put resurrection for humans into the future and into a different place. Jesus rebuked her and instructed her, saying His life is more than a spiritual life; rather, His life is everyday life (a life that affects the physical), and it is here and now by faith.
The Foundation, the Now, and the Dominating Control of Grace
In verse 16 we are “declared righteous” (i.e. justification) by God our Father, who is the one and only ultimate Lawgiver.
In verse 19 we are made into righteousness. That is, after declaring that we are the righteousness of God, God then uses His power and might to make our thoughts and actions righteous. Thus, the more foundational issue is found in verse 16 because when God the judge declares something, He has the integrity to make it happen.
In verse 21 we are under the almighty power of God’s direct control. With the foundation of being declared righteous, the unmerited favor of God dominates and controls (like a puppet on a string) us to fully possess the abundance and eternal life in Jesus Christ. That is, as Jesus is in exceedingly-powerful life at the Father’s right hand, we pray for God’s Will to be done on earth, so that we have the same life, because He is our life. Or as John 4:17 says, “As He is, so are we now in this world.”