“Therefore,” as we know, is a key word in the study of logic … It is not strange, then, that we find this word used, in one form or another, no less than 70 times in the Romans Epistle, for Romans is a logical, as well as a theological, treatise.
… The word “therefore” stands out prominently in Paul’s discussion of the logic of the plan of salvation, in which he presents a series of logical propositions.
The first of these propositions is found in Romans 2:1 where, having proved that all men are sinners, including even the most self-righteous, he declares:
Therefore thou art inexcusable …
Then, demonstrating the fact that the Law cannot justify, but can only condemn the sinner, he offers his second logical proposition in Romans 3:20:
Therefore by the deeds of the law there shall no flesh be justified in His [God’s] sight …
Following this declaration with the good news that now the righteousness of God without the law is manifested … through the redemption that is in Christ Jesus, he takes a third logical step in the proposition of Romans 3:28:
Therefore we conclude that a man is justified by faith without the deeds of the law.
Then an in-depth discussion of the imputation of the believer’s sins to Christ and of Christ’s righteousness to the believer leads the Apostle to his fourth logical proposition in Romans 5:1:
Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.
This, in turn, leads him into a discussion of the believer’s deliverance from the bondage of sin (Chapter 6) and of the Law (Chapter 7), to his fifth logical proposition in Romans 8:1:
There is therefore now no condemnation to them which are in Christ Jesus.
This proposition is his introduction to a precious chapter, in which the utter inefficacy of the Law is set over against the glorious efficacy of the Holy Spirit’s working in and through the believer, a chapter which opens with “no condemnation” and closes with “no separation.” — The Epistle of Paul to the Romans, page 180-181.