John Calvin Commentary Romans 3:26

"for the showing, [I say], of his righteousness at this present season: that he might himself be just, and the justifier of him that hath faith in Jesus." — Romans 3:26 (ASV)

For a demonstration, etc. The repetition of this clause is emphatic; and Paul, therefore, made this repetition, accepting its great necessity, for nothing is more difficult than to persuade people that they ought to renounce all things as their own and attribute them all to God. At the same time, this demonstration was intentionally mentioned twice so that the Jews might open their eyes to behold it.

At this time, etc. What had always been true, Paul applies to the time when Christ was revealed, and not without reason; for what was formerly known obscurely under shadows, God openly manifested in his Son. So the coming of Christ was the time of his good pleasure and the day of salvation. God had indeed in all ages given some evidence of his righteousness, but it appeared far brighter when the Sun of Righteousness shone. Therefore, the comparison between the Old and the New Testament ought to be noted, for only then, when Christ appeared, was the righteousness of God revealed.

That he might be just, etc. This is a definition of that righteousness which Paul has declared was revealed when Christ was given, and which, as Paul has taught us in the first chapter, is made known in the gospel. Paul affirms that it consists of two parts. The first is that God is just—not indeed as one among many, but as one who contains within himself all fullness of righteousness. For complete and full praise, such as is due, is given to him only when he alone obtains the name and the honor of being just, while the whole human race is condemned for injustice. The other part refers to the communication of righteousness, for God by no means keeps his riches laid up in himself but pours them forth upon people. Then the righteousness of God shines in us whenever God justifies us by faith in Christ; for Christ would have been given to us for righteousness in vain, if there were no fruition of him by faith. It therefore follows that all people were unjust and lost in themselves until a remedy from heaven was offered to them.