St. Paul’s great Epistle to the Romans has much to say about “the righteousness of God”; in fact, this is the theme of the Book of Romans.
Every man, woman and child should know about the righteousness of God — or, to simplify the word — the rightness of God. It is most important to understand that God does always and only that which is right. He can do nothing and will do nothing that is not right.
Thus God cannot and does not merely forgive sinners and smuggle them into heaven, for this would not be right. As Job 8:20 says, “Behold, God will not cast away a perfect man, neither will He help evil doers,” for neither would be right.
It was Bildad who said this to Job, and Job replied, almost exasperated: “I know it is so of a truth, but how shall a man be just with God?” (Job 9:2). In other words, how can a holy God look upon a sinner and pronounce him righteous? With this background let us consider Paul’s great declaration in Romans 1:16,17:
“I am not ashamed of the gospel of Christ, for it is the power of God unto salvation to everyone that believeth…. for therein is the righteousness [i.e., the rightness] of God revealed….”
True, the love of God is also revealed in the gospel, but what made Paul so proud to proclaim the gospel is the fact that it tells how God dealt “righteously,” or rightly, with sin, paying its just penalty Himself at Calvary so that He might offer salvation to all by free grace.
Thus the Apostle declares in Romans 6:23: “The wages of sin is death [this is its just penalty] but the [free] gift of God is eternal life through Jesus Christ, our Lord.” source