“The law was given to men through Moses, but it did not originate with Moses. It had existed in the heart of God from before the foundation of the world. On Mount Sinai it became the legal code for the nation of Israel; but the moral principles it embodies are eternal. The spring of Christian morality is the love of Christ, not the law of Moses; nevertheless there has been no abrogation of the principles of morality contained in the law. No privileged class exists exempt from that righteousness which the law enjoins.” A.W. Tozer
“Mercy is an attribute of God, an infinite and inexhaustible energy within the divine nature which disposes God to be actively compassionate. Both the Old and the New Testaments proclaim the mercy of God. We should banish from our minds forever the common but erroneous notion that justice and judgment characterize the God of Israel, while mercy and grace belong to the Lord of the Church. Actually there is in principle no difference between the Old Testament and the New.”
“In God mercy and grace are one; but as they reach us they are seen as two, related but not identical. As mercy is God’s goodness confronting human misery and guilt, so grace is His goodness directed toward human debt and demerit. It is by His grace that God imputes merit where none previously existed and declares no debt to be where one had been before. Grace is the good pleasure of God that inclines Him to bestow benefits upon the undeserving. It is a self-existent principle inherent in the divine nature and appears to us as a self-caused propensity to pity the wretched, spare the guilty, welcome the outcast, and bring into favor those who were before under just disapprobation. Its use to us sinful men is to save us and make us sit together in heavenly places to demonstrate to the ages the exceeding riches of God’s kindness to us in Christ Jesus.”
“We benefit eternally by God’s being just what He is. Because He is what He is, He lifts up our heads out of the prison house, changes our prison garments for royal robes, and makes us to eat bread continually before Him all the days of our lives. Grace takes its rise far back in the heart of God, in the awful and incomprehensible abyss of His holy being; but the channel through which it flows out to men is Jesus Christ, crucified and risen. The apostle Paul, who beyond all others is the exponent of grace in redemption, never disassociates God’s grace from God’s crucified Son. Always in his teachings the two are found together, organically one and inseparable. (Ephesians 1:5-7)”
“John also in the Gospel that bears his name identifies Christ as the medium through which grace reaches mankind: “For the law was given by Moses, but grace and truth came by Jesus Christ.” But right here it is easy to miss the path and go far astray from the truth; and some have done this. They have compelled this verse to stand by itself, unrelated to other Scriptures bearing on the doctrine of grace, and have made it teach that Moses knew only law and Christ knows only grace. So the Old Testament is made to be a book of law and the New Testament a book of grace. The truth is quite otherwise.
The law was given to men through Moses, but it did not originate with Moses. It had existed in the heart of God from before the foundation of the world. On Mount Sinai it became the legal code for the nation of Israel; but the moral principles it embodies are eternal. The spring of Christian morality is the love of Christ, not the law of Moses; nevertheless there has been no abrogation of the principles of morality contained in the law. No privileged class exists exempt from that righteousness which the law enjoins.
The Old Testament is indeed a book of law, but not of law only. Before the great flood Noah “found grace in the eyes of the Lord,” and after the law was given God said to Moses, “Thou hast found grace in my sight.” No one was ever saved other than by grace, from Abel to the present moment. Grace indeed came by Jesus Christ, but it did not wait for His birth in the manger or His death on the cross before it became operative. Christ is the Lamb slain from the foundation of the world. The first man in human history to be reinstated in the fellowship of God came through faith in Christ. In olden times men looked forward to Christ’s redeeming work; in later times they gaze back upon it, but always they came and they come by grace, through faith.
We must keep in mind also that the grace of God is infinite and eternal. Instead of straining to comprehend this as a theological truth, it would be better and simpler to compare God’s grace with our need. We can never know the enormity of our sin. What we can know is that “where sin abounded, grace did much more abound.” Who shall define the limitless grace of God? Its “much more” plunges our thoughts into infinitude and confounds them there. All thanks be to God for grace abounding!”
A W Tozer – The Mercy and the Grace of God (selective quotes, emphasis in bold are mine)