21 But now the righteousness of God apart from the law is revealed, being witnessed by the Law and the Prophets,
being witnessed [attested] by the Law [expression of God’s character] and the Prophets [the Old Testament],
The phrase “Law and the Prophets” is Bible parlance for the full Old Testament. The gospel was no afterthought by God. The Law and the Prophets testifying to righteousness apart from works is God’s standard for salvation. Justification by faith was taught in the Old Testament as well. The Old Testament foreshadowed justification by faith. Justification by faith was not a new discovery in the New Testament. It was clearly known in the Old Testament.
We want to earn our salvation but God wants to give it.
We want to earn our salvation but God wants to give it. He does this apart from the law. A mirror does not cleanse dirt from our face; it merely shows that dirt is there. That is the main function of the law. Laws in a given state do not vindicate its citizens but are there to incriminate those who break them. We demonstrate the laws of the state for the purpose of conviction and judgment.
Fundamentally, there are two ways to gain God’s favor: (1) human achievement, (2) God’s provision of grace. The law shows man’s complete incapacity to come to God by his own righteousness or morality. God views man’s righteousness as “filthy rags” (menstrual cloths, Is 64:6).