For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh. Romans 8:3
The requirements of the law were righteous; the problem with them was that, only righteous people could meet those requirements. And here was fallen man being asked to live righteous; akin to asking a fish to show dexterity at climbing trees.
God knew that man could not actually fulfill the requirements of the law, and so the law was given only as an interim measure, until such a time when true righteousness was to be revealed in Christ Jesus. And so Paul says that, before faith came, we were kept under the law, shut up unto the faith, which should afterwards be revealed. Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. Gal 3:23-24
Now the notion of a schoolmaster conjures the image of a stern enforcer whose only joy is to keep everyone in line with a list of dos and don’ts. He is mostly removed from the actual situations in which the pupil learns. The teacher plays this role of instructing the pupil better. This is why the bible speaks in such terms of grace: For the grace of God that bringeth salvation hath appeared to all men, Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; Titus 2:11-12
The law then being schoolmaster only demanded that we live righteously or suffer the peril of death. Grace appeared however unto all men and came alongside us to teach us how to live godly (fulfill the requirements of the law) in this present world. You might say that while the law gave the exam without teaching the curriculum, grace taught us – by the example of Christ’s life, how we ought to tackle the daily tests by which our lives are examined.
Importantly, Grace does not merely try to teach a fish how to climb a tree, for it knows the futility of that. What it does first is as that verse says – “bring salvation”. God recognized that because of our flesh, we could not fulfill the requirements of righteousness. He therefore sent Christ in the form of sinful flesh to swap places with us (on the cross) and obtain righteousness on our behalf.
Lord, let your grace abound unto righteousness in my life.