Jonathan Edwards: “The only way we can know whether we are sinning is by knowing His Moral Law.”
John Newton (wrote "Amazing Grace"): “Ignorance of the nature and design of the Law is at the bottom of most religious mistakes.”
D. L. Moody: “Ask Paul why [the Law] was given. Here is his answer, ‘That every mouth may be stopped, and all the world may become guilty before God’ (Romans 3:19). The Law stops every man’s mouth. I can always tell a man who is near the kingdom of God; his mouth is stopped. This, then, is why God gives us the Law—to show us ourselves in our true colors.”
Charles Finney: “Ever more the Law must prepare the way for the Gospel. To overlook this in instructing souls, is almost certain to result in false hope, the introduction of a false standard of Christian experience, and to fill the Church with false converts... time will make this plain.”
Please know them and memorize them. I will leave you with what Paul said about the Law and Christ
Gal 3:24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.