Treasury of Scripture Knowledge: Adam is the "type" (pattern or resemblance) of him who was to come, i.e., THE MESSIAH). It is indeed interesting to compare, on Scripture authority, Adam as the root of sin and death to all, with CHRIST, who is to all true Christians the root of holiness and life.

 

Barnes Notes on the New Testament: Death reigned. Under his dark and withering reign people sank down to the grave. We have a similar expression when we represent death as "the king of terrors." It is a striking and affecting personification, for:

(1) His reign is absolute. He strikes down whom he pleases and when he pleases.

 

(2) There is no escape. All must bow to his scepter and be humbled beneath his hand.

 

(3) It is universal. Old and young alike are the subjects of his gloomy empire.

 

(4) It would be an eternal reign if it were not for the gospel. It would shed unmitigated woes upon the earth; and the silent tread of this terrible king would produce only desolation and tears forever.

Albert Barnes: By one man’s offence--or, by one offence."If, under the administration of a just and merciful Being it has occurred that, by the offence of one, death hath exerted so wide a dominion, we have reason much more to expect...that they who are brought under his plan of saving mercy shall be brought to new life.

 

They which receive abundance of grace--the abundant favor; the mercy that shall counterbalance and surpass the evils introduced by the sin of Adam. That favor shall be more than sufficient to counterbalance all those evils. The evils which they suffer in consequence of the sin of Adam bear no comparison with the mercies of eternal life that shall flow to them from the work of the Savior.

 

The gift of righteousness--this stands opposed to the evils introduced by Adam. As the effect of his sin was to produce condemnation, so here the gift of righteousness refers to the opposite, to pardon, to justification, to acceptance with God. To show that people were thus justified by the gospel was the leading design of the apostle; and the argument here is that if by one man’s sin death reigned over those who were under condemnation...we have much more reason to suppose that they who are delivered from sin by the death of Christ, and accepted of God, shall reign with him in life.

 

Shall reign--the word "reign" is often applied to the condition of saints in heaven, 2 Tim 2:12, "If we suffer, we shall also reign with him"; Rev 5:10; 20:6; 22:5. It means that they shall be exalted to a glorious state of happiness in heaven; that they shall be triumphant over all their enemies; shall gain an ultimate victory; and shall partake with the Captain of their salvation in the splendors of his dominion above, Rev 3:21; Luke 22:30.

 

In life--this stands opposed to the death that reigned as the consequence of the sin of Adam. It denotes complete freedom from condemnation; from temporal death; from sickness, pain, and sin. It is the usual expression to denote the complete bliss of the saints in glory; note, John 3:36.

 

By one, Jesus Christ--as the consequence of his work. The apostle here does not state the mode or manner in which this was done; nor does he say that it was perfectly parallel in the mode with the effects of the sin of Adam. He is comparing the results or consequences of the sin of the one and of the work of the other. There is a similarity in the consequences. The way in which the work of Christ had contributed to this he had stated in Rom 3:24, 28.