Thought from Today's Old Testament Passage:
And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more. — Jeremiah xxxi. 34.
If we regard the passage before us as instructive in its order, the knowledge of God follows close upon the application of the law to the heart. Read, "After those days, saith the Lord, I will put My law in their inward parts, and write it in their hearts; and will be their God and they shall be My people…, and they shall all know Me, from the least of them unto the greatest of them, saith the Lord" [v. 33-34]. The work of grace usually begins, so far as we can perceive it, by the Holy Spirit's bringing the law into contact with the inner man. The law outside of a man is forgotten; he may profess a reverence for it, but it does not affect his desires and thoughts. But when the Holy Spirit begins to put the law into the inward parts, the immediate result is the discovery of our shortcomings and transgressions. The more the man's heart sees the perfect holiness of the law of God, the more he perceives his own unholiness and impurity. He sets his own conduct in contrast with the divine righteousness, and he is overwhelmed with shame, sorrow, and dismay. He feels that if God should mark iniquities, he could not stand in His presence; yea more, that if the Lord at once condemned him, He would be just. Law-work is grace-work in its darker dress.
Charles H. Spurgeon, The Treasury of the Bible, Vol. 4 (Grand Rapids, MI: Zondervan, 1962), p. 136.