THE SPRING OF CHRISTIAN MORALITY
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. There never was a time when the law did not represent the will of God for mankind nor a time when the violation of it did not bring its own penalty, though God was patient and sometimes "winked" at wrongdoing because of the ignorance of the people. Paul's close-knit arguments in the third and fifth chapters of his epistle to the Romans make this very clear. 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 that the law enjoins.
This righteousness from God comes through faith in Jesus Christ to all who believe. There is no difference, for all have sinned and fall short of the glory of God.
The law existed in the heart of God from before the foundation of the world.
Your grace and truth come through Your Son, Father God, so we praise Your name for the gift of salvation.