Law and Gospel
The Law is good. The Law is perfect and holy. There is no defect in the Law of God. The problem is not the Law itself but that man is a sinner by nature and cannot keep the Law. Through the law comes the knowledge of sin. Rather than curb sin, the law brings sin out into the open, revealing to us the depths of our human, sinful depravity.
Imagine a large plane glass window. You can break it by driving a tank through it, or you can simply fire the smallest pellet from a gun through the glass, but in both cases, the glass is broken and needs to be replaced. In the same way, to break even one of Godâ€™s commandments makes a person guilty of breaking it all. As James 2:10 reminds us, â€œFor whoever keeps the whole law but fails in one point has become accountable for all of it.â€
Man as a sinner cannot keep the Law and to fail to keep it in one part makes us guilty of breaking it all. Thatâ€™s because the law is a complete set of requirements and we have broken it. We have all commited high treason deliberately.
The Law was given not to make people righteous but in fact to forever shut menâ€™s mouths regarding any attempt at self justification before God. The Law reveals sin, and knowing the holiness and righteousness of God, it shows us our desperate condition before Him. When the Law does it work, it reveals sin to the point that we understand the justice we deserve and cry out for intervention from a Savior. That is why even in the Old Covenant Law system, there were sacrifices of atonement for sin, pointing us to One who would come and remove sin by His perfect sacrifice as the Lamb of God.
The Law reveals the holiness of God, the exceeding sinfulness of our sin, and its remedy in the sin bearing substitute lamb. More on this here. - JS