We know that the law is good if one uses it properly. We also know that law is made not for the righteous but for lawbreakers and rebels, the ungodly and sinful, the unholy and irreligious; for those who kill their fathers or mothers, for murderers, for adulterers and perverts, for slave traders and liars and perjurers—and for whatever else is contrary to the sound doctrine that conforms to the glorious gospel of the blessed God, which he entrusted to me.
1 Timothy 1:8-11
The Law is like a set of training wheels. They are for people who don't know how to ride a bike, not for people who do. The Law is for people who are unrighteous, not for the righteous.
This, of course, doesn't mean that 'the righteous' can break the law, anymore than people who know how to ride a bike should try to tip over sideways now that the training wheels are no longer in the way. Rather, 'the righteous' will live according to the law without trying! There is no 'obedience' necessary for those whose natural course of action is 'righteousness,' just as one who knows how to ride a bike will remain upright without the training wheels to hold them up.
As Dr Willard says, "The Law is, has been, and always will be, the course of righteousness..."
Until the time when we were mature enough to respond freely in faith to the living God, we were carefully surrounded and protected by the Mosaic law. The law was like those Greek tutors, with which you are familiar, who escort children to school and protect them from danger or distraction, making sure the children will really get to the place they set out for.